Rezerla

Rezerla Post List Field Search adds a Search in dropdown next to the search box on post list screens (<code>edit.php</code>). Search by title, content, slug, custom fields, post meta, or taxonomy — individually or across all configured fields at once.
<ul>
<li>Admin-only — no impact on front-end search</li>
<li>Per post type configuration</li>
<li>Core fields, post meta, and taxonomies</li>
<li>Optional list table columns (Show in table checkbox)</li>
<li>Temporary column and highlight when searching by a single field</li>
<li>Field discovery for meta keys and taxonomies</li>
<li>Lightweight — no frameworks or subscriptions</li>
<li>Default configuration for WP Store Locator (<code>wpsl_stores</code>)</li>
<li>No data collection or external API calls</li>
<li>Translations: English (default), Polish, German, French, Spanish, Italian</li>
</ul>
<h3>Usage example</h3>
On a WP Store Locator store list (<code>edit.php?post_type=wpsl_stores</code>):
<ol>
<li>Enter “Katowice” in the search box.</li>
<li>Select City in the dropdown.</li>
<li>Click the search button.</li>
</ol>
URL: <code>edit.php?post_type=wpsl_stores&s=Katowice&rezerla_plfs_field=city</code>
<h3>List table columns</h3>
Check Show in table in field settings to display meta or taxonomy values on the list. 
When searching by a single field, that column appears temporarily and is highlighted even without the checkbox.

Rezerla Post List Field Search

Adds a configurable "Search in" dropdown to WordPress admin post lists for searching by title, content, slug, meta, and taxonomies.

meloniq

Enhance the default WordPress admin search by including custom fields (post meta) in search results. 
This plugin seamlessly extends the post listing (edit.php) search functionality, allowing administrators to quickly find content based on values stored in custom fields.
It works out of the box with no configuration required—just activate and start searching. 
Especially useful for sites that rely heavily on custom fields, such as those built with ACF or other meta-based data structures.
Lightweight, efficient, and fully integrated with the native WordPress admin experience.

WP-Admin Search Post Meta

Search WordPress admin posts by custom fields (post meta) directly from the default search.

Rezerla Post List Field Search vs WP-Admin Search Post Meta