diff --git a/ui/src/pages/admin/rbac/DashboardTab.tsx b/ui/src/pages/admin/rbac/DashboardTab.tsx
index df6985d6..6e5abfb5 100644
--- a/ui/src/pages/admin/rbac/DashboardTab.tsx
+++ b/ui/src/pages/admin/rbac/DashboardTab.tsx
@@ -1,38 +1,72 @@
-import { useRbacStats, useGroups, useRoles } from '../../../api/queries/admin/rbac';
-import type { GroupDetail, RoleDetail } from '../../../api/queries/admin/rbac';
+import { useMemo } from 'react';
+import { useRbacStats, useGroups } from '../../../api/queries/admin/rbac';
+import type { GroupDetail } from '../../../api/queries/admin/rbac';
 import styles from './RbacPage.module.css';
 
 export function DashboardTab() {
   const stats = useRbacStats();
   const groups = useGroups();
-  const roles = useRoles();
+
+  const groupList: GroupDetail[] = groups.data ?? [];
+
+  // Build inheritance diagram data: top-level groups sorted alphabetically,
+  // children sorted alphabetically and indented below their parent.
+  const { topLevelGroups, childMap } = useMemo(() => {
+    const sorted = [...groupList].sort((a, b) => a.name.localeCompare(b.name));
+    const top = sorted.filter((g) => !g.parentGroupId);
+    const cMap = new Map<string, GroupDetail[]>();
+    for (const g of sorted) {
+      if (g.parentGroupId) {
+        const children = cMap.get(g.parentGroupId) ?? [];
+        children.push(g);
+        cMap.set(g.parentGroupId, children);
+      }
+    }
+    return { topLevelGroups: top, childMap: cMap };
+  }, [groupList]);
+
+  // Derive roles from groups in tree order (top-level then children), collecting
+  // each group's directRoles, deduplicating by id and preserving first-seen order.
+  const roleList = useMemo(() => {
+    const seen = new Set<string>();
+    const result: { id: string; name: string }[] = [];
+    for (const g of topLevelGroups) {
+      for (const r of g.directRoles) {
+        if (!seen.has(r.id)) {
+          seen.add(r.id);
+          result.push(r);
+        }
+      }
+      for (const child of childMap.get(g.id) ?? []) {
+        for (const r of child.directRoles) {
+          if (!seen.has(r.id)) {
+            seen.add(r.id);
+            result.push(r);
+          }
+        }
+      }
+    }
+    return result;
+  }, [topLevelGroups, childMap]);
+
+  // Collect unique users from all groups, sorted alphabetically by displayName.
+  const allUsers = useMemo(() => {
+    const userMap = new Map<string, string>();
+    for (const g of groupList) {
+      for (const m of g.members) {
+        userMap.set(m.userId, m.displayName);
+      }
+    }
+    return new Map(
+      [...userMap.entries()].sort((a, b) => a[1].localeCompare(b[1]))
+    );
+  }, [groupList]);
 
   if (stats.isLoading) {
     return <div className={styles.loading}>Loading...</div>;
   }
 
   const s = stats.data;
-  const groupList: GroupDetail[] = groups.data ?? [];
-  const roleList: RoleDetail[] = roles.data ?? [];
-
-  // Build inheritance diagram data
-  const topLevelGroups = groupList.filter((g) => !g.parentGroupId);
-  const childMap = new Map<string, GroupDetail[]>();
-  for (const g of groupList) {
-    if (g.parentGroupId) {
-      const children = childMap.get(g.parentGroupId) ?? [];
-      children.push(g);
-      childMap.set(g.parentGroupId, children);
-    }
-  }
-
-  // Collect unique users from all groups
-  const allUsers = new Map<string, string>();
-  for (const g of groupList) {
-    for (const m of g.members) {
-      allUsers.set(m.userId, m.displayName);
-    }
-  }
 
   return (
     <div>