diff --git a/src/lib/components/contents/details/preview/field-preview.svelte b/src/lib/components/contents/details/preview/field-preview.svelte
index 2e0060d6..03231756 100644
--- a/src/lib/components/contents/details/preview/field-preview.svelte
+++ b/src/lib/components/contents/details/preview/field-preview.svelte
@@ -2,10 +2,7 @@
   import { escapeRegExp } from '@sveltia/utils/string';
   import { previews } from '$lib/components/contents/details/widgets';
   import { entryDraft } from '$lib/services/contents/draft';
-  import {
-    joinExpanderKeyPathSegments,
-    syncExpanderStates,
-  } from '$lib/services/contents/draft/editor';
+  import { getExpanderKeys, syncExpanderStates } from '$lib/services/contents/draft/editor';
   import { defaultI18nConfig } from '$lib/services/contents/i18n';
 
   /**
@@ -33,8 +30,9 @@
     ? /** @type {RelationField | SelectField} */ (fieldConfig).multiple
     : undefined;
   $: isList = widgetName === 'list' || (hasMultiple && multiple);
-  $: ({ collection, collectionFile, currentValues } =
+  $: ({ collectionName, fileName, collection, collectionFile, currentValues } =
     $entryDraft ?? /** @type {EntryDraft} */ ({}));
+  $: valueMap = currentValues[locale];
   $: ({ i18nEnabled, defaultLocale } = (collectionFile ?? collection)?._i18n ?? defaultI18nConfig);
   $: canTranslate = i18nEnabled && (i18n === true || i18n === 'translate');
   $: canDuplicate = i18nEnabled && i18n === 'duplicate';
@@ -42,11 +40,11 @@
 
   // Multiple values are flattened in the value map object
   $: currentValue = isList
-    ? Object.entries(currentValues[locale])
+    ? Object.entries(valueMap)
         .filter(([_keyPath]) => _keyPath.match(keyPathRegex))
         .map(([, val]) => val)
         .filter((val) => val !== undefined)
-    : currentValues[locale][keyPath];
+    : valueMap[keyPath];
 
   /**
    * Called whenever the preview field is clicked. Highlight the corresponding editor field by
@@ -55,9 +53,7 @@
   const highlightEditorField = () => {
     syncExpanderStates(
       Object.fromEntries(
-        keyPath
-          .split('.')
-          .map((_key, index, arr) => [joinExpanderKeyPathSegments(arr, index + 1), true]),
+        getExpanderKeys({ collectionName, fileName, valueMap, keyPath }).map((key) => [key, true]),
       ),
     );
 
diff --git a/src/lib/components/contents/details/widgets/list/list-editor.svelte b/src/lib/components/contents/details/widgets/list/list-editor.svelte
index 9df69835..0460819e 100644
--- a/src/lib/components/contents/details/widgets/list/list-editor.svelte
+++ b/src/lib/components/contents/details/widgets/list/list-editor.svelte
@@ -121,7 +121,13 @@
     // Initialize the expander state
     syncExpanderStates({
       [parentExpandedKeyPath]: !minimizeCollapsed,
-      ...Object.fromEntries(items.map((__, index) => [`${keyPath}.${index}`, !collapsed])),
+      ...Object.fromEntries(
+        items.map((__, index) => {
+          const key = `${keyPath}.${index}`;
+
+          return [key, expanderStates?._[key] ?? !collapsed];
+        }),
+      ),
     });
   });
 
diff --git a/src/lib/components/contents/details/widgets/object/object-editor.svelte b/src/lib/components/contents/details/widgets/object/object-editor.svelte
index 3c4b167b..97054d22 100644
--- a/src/lib/components/contents/details/widgets/object/object-editor.svelte
+++ b/src/lib/components/contents/details/widgets/object/object-editor.svelte
@@ -100,7 +100,9 @@
     widgetId = generateUUID('short');
 
     // Initialize the expander state
-    syncExpanderStates({ [parentExpandedKeyPath]: !collapsed });
+    syncExpanderStates({
+      [parentExpandedKeyPath]: expanderStates?._[parentExpandedKeyPath] ?? !collapsed,
+    });
   });
 
   /**
diff --git a/src/lib/services/contents/draft/editor.js b/src/lib/services/contents/draft/editor.js
index 31fd4e53..cfc314f0 100644
--- a/src/lib/services/contents/draft/editor.js
+++ b/src/lib/services/contents/draft/editor.js
@@ -1,8 +1,9 @@
 import { IndexedDB, LocalStorage } from '@sveltia/utils/storage';
 import equal from 'fast-deep-equal';
 import { get, writable } from 'svelte/store';
-import { entryDraft } from '$lib/services/contents/draft';
 import { backend } from '$lib/services/backends';
+import { entryDraft } from '$lib/services/contents/draft';
+import { getFieldConfig } from '$lib/services/contents/entry';
 
 /** @type {IndexedDB | null | undefined} */
 let settingsDB = undefined;
@@ -76,30 +77,75 @@ export const syncExpanderStates = (stateMap) => {
 };
 
 /**
- * Join key path segments for the expander UI state.
- * @param {string[]} arr - Key path array, e.g. `testimonials.0.authors.2.foo.bar`.
- * @param {number} end - End index for `Array.slice()`.
- * @returns {string} Joined string, e.g. `testimonials.0.authors.10.foo#.bar#`.
+ * Get a list of keys for the expander states, given the key path. The returned keys could include
+ * nested lists and objects.
+ * @param {object} args - Partial arguments for {@link getFieldConfig}.
+ * @param {string} args.collectionName - Collection name.
+ * @param {string} [args.fileName] - File name.
+ * @param {FlattenedEntryContent} args.valueMap - Object holding current entry values.
+ * @param {FieldKeyPath} args.keyPath - Key path, e.g. `testimonials.0.authors.2.foo`.
+ * @returns {string[]} Keys, e.g. `['testimonials', 'testimonials.0', 'testimonials.0.authors',
+ * 'testimonials.0.authors.2', 'testimonials.0.authors.2.foo']`.
  */
-export const joinExpanderKeyPathSegments = (arr, end) =>
-  arr
-    .slice(0, end)
-    .map((k) => `${k}#`)
-    .join('.')
-    .replaceAll(/#\.(\d+)#/g, '.$1');
+export const getExpanderKeys = ({ collectionName, fileName, valueMap, keyPath }) => {
+  const keys = new Set();
+
+  keyPath.split('.').forEach((_keyPart, index, arr) => {
+    const _keyPath = arr.slice(0, index + 1).join('.');
+    const config = getFieldConfig({ collectionName, fileName, valueMap, keyPath: _keyPath });
+
+    if (config?.widget === 'object') {
+      if (_keyPath.match(/\.\d+$/)) {
+        keys.add(_keyPath);
+      }
+
+      keys.add(`${_keyPath}#`);
+    } else if (config?.widget === 'list') {
+      keys.add(_keyPath.match(/\.\d+$/) ? _keyPath : `${_keyPath}#`);
+    } else if (index > 0) {
+      const parentKeyPath = arr.slice(0, index).join('.');
+
+      const parentConfig = getFieldConfig({
+        collectionName,
+        fileName,
+        valueMap,
+        keyPath: parentKeyPath,
+      });
+
+      if (parentConfig?.widget === 'object' && /** @type {ObjectField} */ (parentConfig).fields) {
+        keys.add(`${parentKeyPath}.${parentConfig.name}#`);
+      }
+
+      if (parentConfig?.widget === 'list' && /** @type {ListField} */ (parentConfig).field) {
+        keys.add(_keyPath);
+      }
+    }
+  });
+
+  return [...keys];
+};
 
 /**
  * Expand any invalid fields, including the parent list/object(s).
+ * @param {object} args - Partial arguments for {@link getFieldConfig}.
+ * @param {string} args.collectionName - Collection name.
+ * @param {string} [args.fileName] - File name.
+ * @param {Record<LocaleCode, FlattenedEntryContent>} args.currentValues - Field values.
  */
-export const expandInvalidFields = () => {
+export const expandInvalidFields = ({ collectionName, fileName, currentValues }) => {
   /** @type {Record<FieldKeyPath, boolean>} */
   const stateMap = {};
 
-  Object.values(get(entryDraft)?.validities ?? {}).forEach((validities) => {
+  Object.entries(get(entryDraft)?.validities ?? {}).forEach(([locale, validities]) => {
     Object.entries(validities).forEach(([keyPath, { valid }]) => {
       if (!valid) {
-        keyPath.split('.').forEach((_key, index, arr) => {
-          stateMap[joinExpanderKeyPathSegments(arr, index + 1)] = true;
+        getExpanderKeys({
+          collectionName,
+          fileName,
+          valueMap: currentValues[locale],
+          keyPath,
+        }).forEach((key) => {
+          stateMap[key] = true;
         });
       }
     });
diff --git a/src/lib/services/contents/draft/save.js b/src/lib/services/contents/draft/save.js
index e0fe5a1a..3c32010c 100644
--- a/src/lib/services/contents/draft/save.js
+++ b/src/lib/services/contents/draft/save.js
@@ -574,13 +574,6 @@ export const createSavingEntryData = async ({
  * @throws {Error} When the entry could not be validated or saved.
  */
 export const saveEntry = async ({ skipCI = undefined } = {}) => {
-  if (!validateEntry()) {
-    expandInvalidFields();
-
-    throw new Error('validation_failed');
-  }
-
-  const _user = /** @type {User} */ (get(user));
   const draft = /** @type {EntryDraft} */ (get(entryDraft));
 
   const {
@@ -596,6 +589,14 @@ export const saveEntry = async ({ skipCI = undefined } = {}) => {
     files,
   } = draft;
 
+  if (!validateEntry()) {
+    expandInvalidFields({ collectionName, fileName, currentValues });
+
+    throw new Error('validation_failed');
+  }
+
+  const _user = /** @type {User} */ (get(user));
+
   const {
     identifier_field: identifierField = 'title',
     slug: slugTemplate = `{{${identifierField}}}`,