src/components/Dashboard/Dashboard.models.ts

@@ -1,6 +1,7 @@
 import * as React from "react";
 import {
-  ReportData
+  ReportData,
+  GroupKey,
 } from "../../features/report";
 
 export type DashboardMode = "expense" | "income";
@@ -11,6 +12,7 @@ export interface DashboardState {
   mode: DashboardMode;
   periodType: DashboardPeriodType;
   selectedPeriodId: DashboardSelectedPeriodId;
+  selectedGroupKey: GroupKey | null;
   comparison: boolean;
 }
 

src/components/Dashboard/Dashboard.tsx

@@ -7,6 +7,7 @@ export default function Dashboard(props: DashboardProps) {
     mode: "expense",
     periodType: "rolling",
     selectedPeriodId: null,
+    selectedGroupKey: null,
     comparison: false,
   });
 
@@ -35,6 +36,10 @@ export default function Dashboard(props: DashboardProps) {
     setState(prev => ({ ...prev, selectedPeriodId }));
   };
 
+  const setSelectedGroupKey = (groupKey: typeof state.selectedGroupKey) => {
+    setState(prev => ({ ...prev, selectedGroupKey: groupKey }));
+  };
+
   return (
     <DashboardView
       {...props}
@@ -44,6 +49,7 @@ export default function Dashboard(props: DashboardProps) {
       togglePeriodType={togglePeriodType}
       toggleComparison={toggleComparison}
       setSelectedPeriodId={setSelectedPeriodId}
+      setSelectedGroupKey={setSelectedGroupKey}
     />
   );
 }

src/components/Dashboard/Dashboard.view.tsx

@@ -8,6 +8,7 @@ import {
   ToggleButtonGroup
 } from "@mui/material";
 import { useTheme, alpha } from "@mui/material/styles";
+import { GroupKey } from "../../features/report";
 import { DashboardProps, DashboardState } from "./Dashboard.models";
 
 interface ViewProps extends DashboardProps {
@@ -16,6 +17,7 @@ interface ViewProps extends DashboardProps {
   toggleMode: () => void;
   togglePeriodType: () => void;
   setSelectedPeriodId: (id: string | null) => void;
+  setSelectedGroupKey: (groupKey: GroupKey | null) => void;
   toggleComparison: () => void;
 }
 
@@ -28,10 +30,11 @@ export default function DashboardView({
   togglePeriodType,
   toggleComparison,
   setSelectedPeriodId,
+  setSelectedGroupKey,
 }: ViewProps) {
   const theme = useTheme();
   const themeMode = theme.palette.mode;
-  const { mode, periodType, comparison, selectedPeriodId } = state;
+  const { mode, periodType, comparison, selectedPeriodId, selectedGroupKey } = state;
 
   // Resolve colors with fallbacks
   const colors = React.useMemo(() => {
@@ -120,10 +123,12 @@ export default function DashboardView({
                 periodType={periodType}
                 comparison={comparison}
                 selectedPeriodId={selectedPeriodId}
+                selectedGroupKey={selectedGroupKey}
 
                 togglePeriodType={togglePeriodType}
                 toggleComparison={toggleComparison}
                 setSelectedPeriodId={setSelectedPeriodId}
+                setSelectedGroupKey={setSelectedGroupKey}
               />
             </Grid>
           );

src/components/LatestItems/LatestItems.adapter.ts

@@ -1,8 +1,9 @@
-import { ReportData, Transaction } from "../../features/report";
+import { ReportData, Transaction, GroupKey } from "../../features/report";
 import {
   mergeBucketPeriods,
   periodIdToKey,
   formatCurrency,
+  filterBuckets,
 } from "../report.helpers";
 import { LatestItem } from "./LatestItems.models";
 
@@ -11,11 +12,13 @@ import { LatestItem } from "./LatestItems.models";
 function extractTransactions(
   reportData: ReportData,
   selectedPeriodId: string | null,
+  selectedGroupKey: GroupKey | null,
   mode: "expense" | "income"
 ): Transaction[] {
+  const buckets = filterBuckets(reportData.buckets, selectedGroupKey);
   if (selectedPeriodId) {
     const key = periodIdToKey(selectedPeriodId);
-    const periods = mergeBucketPeriods(reportData.buckets, key);
+    const periods = mergeBucketPeriods(buckets, key);
     const selected = periods.find((p) => p.id === selectedPeriodId);
 
     if (!selected) return [];
@@ -25,7 +28,7 @@ function extractTransactions(
       : (selected.incomes.transactions || []);
   }
 
-  const periods = mergeBucketPeriods(reportData.buckets, "full");
+  const periods = mergeBucketPeriods(buckets, "full");
 
   if (!periods.length) return [];
 
@@ -41,9 +44,10 @@ function extractTransactions(
 export function buildLatestItems(
   reportData: ReportData,
   selectedPeriodId: string | null,
+  selectedGroupKey: GroupKey | null,
   mode: "expense" | "income"
 ): LatestItem[] {
-  const txns = extractTransactions(reportData, selectedPeriodId, mode);
+  const txns = extractTransactions(reportData, selectedPeriodId, selectedGroupKey, mode);
 
   return txns
     .filter((t) => (mode === "expense" ? t.amount < 0 : t.amount >= 0))

src/components/LatestItems/LatestItems.tsx

@@ -1,5 +1,5 @@
 import * as React from "react";
-import { ReportData } from "../../features/report";
+import { ReportData, GroupKey } from "../../features/report";
 import { buildLatestItems } from "./LatestItems.adapter";
 import LatestItemsView from "./LatestItems.view";
 
@@ -7,6 +7,7 @@ type Props = {
   reportData: ReportData;
   mode: "expense" | "income";
   selectedPeriodId: string | null;
+  selectedGroupKey?: GroupKey | null;
   accentColor: string;
 };
 
@@ -14,22 +15,23 @@ export default function LatestItems({
   reportData,
   mode,
   selectedPeriodId,
+  selectedGroupKey = null,
   accentColor,
 }: Props) {
   const [visibleCount, setVisibleCount] = React.useState(5);
 
   const allItems = React.useMemo(() => {
-    return buildLatestItems(reportData, selectedPeriodId, mode);
-  }, [reportData, selectedPeriodId, mode]);
+    return buildLatestItems(reportData, selectedPeriodId, selectedGroupKey, mode);
+  }, [reportData, selectedPeriodId, selectedGroupKey, mode]);
 
-  const isPeriodSelected = Boolean(selectedPeriodId);
+  const hasSelection = Boolean(selectedPeriodId) || Boolean(selectedGroupKey);
 
   const visibleItems = React.useMemo(() => {
-    if (!isPeriodSelected) return allItems.slice(0, 5);
+    if (!hasSelection) return allItems.slice(0, 5);
     return allItems.slice(0, visibleCount);
-  }, [allItems, isPeriodSelected, visibleCount]);
+  }, [allItems, hasSelection, visibleCount]);
 
-  const canExpand = isPeriodSelected && visibleCount < allItems.length;
+  const canExpand = hasSelection && visibleCount < allItems.length;
 
   return (
     <LatestItemsView

src/components/ProgressCard/ProgressCard.models.ts

@@ -5,4 +5,6 @@ export interface ProgressCardProps {
   totalAmount: number;
   colorTheme?: "primary" | "secondary" | "error" | "info" | "success" | "warning";
   compact?: boolean;
+  selected?: boolean;
+  onClick?: () => void;
 }

src/components/ProgressCard/ProgressCard.tsx

@@ -18,6 +18,8 @@ export default function ProgressCard(props: ProgressCardProps) {
       formattedProgress={formattedProgress}
       formattedTotal={formattedTotal}
       compact={compact}
+      selected={props.selected}
+      onClick={props.onClick}
     />
   );
 }

src/components/ProgressCard/ProgressCard.view.tsx

@@ -14,6 +14,8 @@ interface ViewProps extends ProgressCardProps {
   percentage: number;
   formattedProgress: string;
   formattedTotal: string;
+  selected?: boolean;
+  onClick?: () => void;
 }
 
 export default function ProgressCardView({
@@ -23,6 +25,8 @@ export default function ProgressCardView({
   formattedProgress,
   formattedTotal,
   compact = false,
+  selected,
+  onClick,
 }: ViewProps) {
   const theme = useTheme();
   const isDark = theme.palette.mode === "dark";
@@ -30,10 +34,14 @@ export default function ProgressCardView({
   return (
     <Paper
       elevation={compact ? 2 : 4}
+      onClick={onClick}
       sx={{
         width: "100%",
         p: compact ? { xs: 2.5, md: 3 } : { xs: 3, md: 4 },
         borderRadius: compact ? 3 : 4,
+        cursor: onClick ? "pointer" : "default",
+        transform: selected ? "scale(1.02)" : "scale(1)",
+        transition: "transform 0.2s ease, box-shadow 0.2s ease",
         background: (theme) => {
           const baseColor = theme.palette[colorTheme]?.main || theme.palette.primary.main;
           const lightColor = theme.palette[colorTheme]?.light || theme.palette.primary.light;
@@ -48,13 +56,19 @@ export default function ProgressCardView({
         justifyContent: "center",
         position: "relative",
         overflow: "hidden",
-        border: isDark ? "1px solid rgba(255,255,255,0.1)" : "none",
-        boxShadow: (theme) =>
-          `0 ${compact ? 6 : 12}px ${compact ? 12 : 24}px -10px ${
+        border: selected 
+          ? `2px solid #fff`
+          : isDark ? "1px solid rgba(255,255,255,0.1)" : "none",
+        boxShadow: (theme) => {
+          const baseShadow = `0 ${compact ? 6 : 12}px ${compact ? 12 : 24}px -10px ${
             isDark
               ? "rgba(0,0,0,0.5)"
               : theme.palette[colorTheme]?.main || theme.palette.primary.main
-          }`,
+          }`;
+          return selected 
+            ? `${baseShadow}, 0 0 0 2px ${theme.palette.background.paper}, 0 0 0 4px ${theme.palette[colorTheme]?.main || theme.palette.primary.main}` 
+            : baseShadow;
+        },
       }}
     >
       <Typography 

src/components/ProgressCard/TopTags.tsx

@@ -1,6 +1,6 @@
 import * as React from "react";
 import { Box } from "@mui/material";
-import { ReportData } from "../../features/report";
+import { ReportData, GroupKey } from "../../features/report";
 import ProgressCard from "./ProgressCard";
 import { extractTopTags } from "./TopTags.adapter";
 
@@ -8,6 +8,8 @@ type Props = {
   reportData: ReportData;
   mode: "expense" | "income";
   selectedPeriodId?: string | null;
+  selectedGroupKey?: GroupKey | null;
+  setSelectedGroupKey?: (key: GroupKey | null) => void;
   compact?: boolean;
 };
 
@@ -15,6 +17,8 @@ export default function TopTags({
   reportData,
   mode,
   selectedPeriodId,
+  selectedGroupKey,
+  setSelectedGroupKey,
   compact = true,
 }: Props) {
   const { items, total } = React.useMemo(() => {
@@ -33,16 +37,25 @@ export default function TopTags({
         gap: 2,
       }}
     >
-      {items.map((item) => (
-        <ProgressCard
-          key={item.tag}
-          header={item.tag}
-          progressAmount={item.amount}
-          totalAmount={total}
-          compact={compact}
-          colorTheme={mode === "expense" ? "error" : "success"}
-        />
-      ))}
+      {items.map((item) => {
+        const isSelected = selectedGroupKey?.tags?.includes(item.tag);
+        return (
+          <ProgressCard
+            key={item.tag}
+            header={item.tag}
+            progressAmount={item.amount}
+            totalAmount={total}
+            compact={compact}
+            colorTheme={mode === "expense" ? "error" : "success"}
+            selected={isSelected}
+            onClick={() => {
+              if (setSelectedGroupKey) {
+                setSelectedGroupKey(isSelected ? null : { tags: [item.tag] });
+              }
+            }}
+          />
+        );
+      })}
     </Box>
   );
 }

src/components/report.helpers.ts

@@ -1,6 +1,7 @@
 import {
   ReportPeriod,
   ReportBucket,
+  GroupKey,
 } from "../features/report";
 
 // ─── Types ────────────────────────────────────────────────────
@@ -112,3 +113,35 @@ export const getPercentage = (progressAmount: number, totalAmount: number) => {
   if (!totalAmount) return 0;
   return Math.min(100, Math.max(0, (progressAmount / totalAmount) * 100));
 };
+
+// ─── Group filtering ──────────────────────────────────────────
+
+/**
+ * Check if a bucket's group_key matches the selected GroupKey.
+ * Every dimension present in `selected` must exist in the bucket
+ * and contain all the selected values.
+ */
+export function matchesGroupKey(
+  bucket: ReportBucket,
+  selected: GroupKey
+): boolean {
+  for (const [dim, values] of Object.entries(selected)) {
+    const bucketValues = bucket.group_key[dim as keyof GroupKey];
+    if (!bucketValues) return false;
+    if (!(values as string[]).every((v) => bucketValues.includes(v)))
+      return false;
+  }
+  return true;
+}
+
+/**
+ * Return only buckets matching the selected group key,
+ * or all buckets if no selection.
+ */
+export function filterBuckets(
+  buckets: ReportBucket[],
+  selectedGroupKey: GroupKey | null
+): ReportBucket[] {
+  if (!selectedGroupKey) return buckets;
+  return buckets.filter((b) => matchesGroupKey(b, selectedGroupKey));
+}

src/features/report/index.ts

@@ -6,6 +6,7 @@ export type {
   ReportData,
   ReportBucket,
   ReportPeriod,
+  GroupKey,
 } from './report.models'
 export {
   prepareReport