diff --git a/lib/types/thread-types.js b/lib/types/thread-types.js
--- a/lib/types/thread-types.js
+++ b/lib/types/thread-types.js
@@ -510,3 +510,5 @@
 // We can show a max of 5 sidebars inline underneath their parent
 // in the chat tab if every one of the displayed sidebars is unread
 export const maxUnreadSidebars = 5;
+
+export type ThreadStoreThreadInfos = { +[id: string]: RawThreadInfo };
diff --git a/native/redux/client-db-utils.js b/native/redux/client-db-utils.js
--- a/native/redux/client-db-utils.js
+++ b/native/redux/client-db-utils.js
@@ -4,6 +4,7 @@
   ClientDBThreadInfo,
   ClientDBThreadStoreOperation,
   RawThreadInfo,
+  ThreadStoreThreadInfos,
 } from 'lib/types/thread-types.js';
 import {
   convertClientDBThreadInfoToRawThreadInfo,
@@ -13,8 +14,6 @@
 import type { AppState } from './state-types.js';
 import { commCoreModule } from '../native-modules.js';
 
-type ThreadStoreThreadInfos = { +[id: string]: RawThreadInfo };
-
 function updateClientDBThreadStoreThreadInfos(
   state: AppState,
   migrationFunc: ThreadStoreThreadInfos => ThreadStoreThreadInfos,
diff --git a/native/redux/persist.js b/native/redux/persist.js
--- a/native/redux/persist.js
+++ b/native/redux/persist.js
@@ -42,10 +42,12 @@
   convertThreadStoreOperationsToClientDBOperations,
 } from 'lib/utils/thread-ops-utils.js';
 
+import { updateClientDBThreadStoreThreadInfos } from './client-db-utils.js';
 import { migrateThreadStoreForEditThreadPermissions } from './edit-thread-permission-migration.js';
 import { persistMigrationForManagePinsThreadPermission } from './manage-pins-permission-migration.js';
 import type { AppState } from './state-types.js';
 import { unshimClientDB } from './unshim-utils.js';
+import { updateRolesAndPermissions } from './update-roles-and-permissions.js';
 import { commCoreModule } from '../native-modules.js';
 import { defaultDeviceCameraInfo } from '../types/camera.js';
 import { defaultGlobalThemeInfo } from '../types/themes.js';
@@ -528,6 +530,8 @@
 
     return state;
   },
+  [38]: state =>
+    updateClientDBThreadStoreThreadInfos(state, updateRolesAndPermissions),
 };
 
 // After migration 31, we'll no longer want to persist `messageStore.messages`
diff --git a/native/redux/update-roles-and-permissions.js b/native/redux/update-roles-and-permissions.js
new file mode 100644
--- /dev/null
+++ b/native/redux/update-roles-and-permissions.js
@@ -0,0 +1,39 @@
+// @flow
+
+import type { ThreadStoreThreadInfos } from 'lib/types/thread-types.js';
+import { values } from 'lib/utils/objects.js';
+
+type ThreadTraversalNode = {
+  +threadID: string,
+  +children: ?$ReadOnlyArray<ThreadTraversalNode>,
+};
+
+function constructThreadTraversalNodes(
+  threadStoreInfos: ThreadStoreThreadInfos,
+): $ReadOnlyArray<ThreadTraversalNode> {
+  const parentThreadMap = {};
+
+  for (const threadInfo of values(threadStoreInfos)) {
+    const parentThreadID = threadInfo.parentThreadID ?? 'root';
+    parentThreadMap[parentThreadID] = [
+      ...(parentThreadMap[parentThreadID] ?? []),
+      threadInfo.id,
+    ];
+  }
+
+  const constructNodes = nodeID => ({
+    threadID: nodeID,
+    children: parentThreadMap[nodeID]?.map(constructNodes) ?? null,
+  });
+
+  return parentThreadMap['root'].map(constructNodes);
+}
+
+function updateRolesAndPermissions(
+  threadStoreInfos: ThreadStoreThreadInfos,
+): ThreadStoreThreadInfos {
+  constructThreadTraversalNodes(threadStoreInfos);
+  return threadStoreInfos;
+}
+
+export { updateRolesAndPermissions };