Magenta Cuda

This <a href="http://alttypes.wordpress.com/search-types-custom-fields-widget/" rel="nofollow ugc">search widget</a> can search <a href="https://wordpress.org/plugins/types/" rel="ugc">Toolset Types</a> custom posts by the value of Toolset Types custom fields, custom taxonomies and parent/child relationships. It is designed to be used with the Toolset Types plugin and makes use of Toolset Types’ proprietary database format to generate user friendly field names and field values. The widget uses user friendly substitutions for the actual values in the database, e.g. post title is substituted for post id in parent/child fields. The selected posts can be displayed as a standard WordPress list of posts, a spreadsheet of posts with their custom fields or a gallery of featured images.
Version 1.3 supports a <a href="https://alttypes.wordpress.com/#spa" rel="nofollow ugc">single-page application mode</a> where the search results returned by an interactive AJAX request populates a <a href="http://backbonejs.org/" rel="nofollow ugc">Backbone.js</a> collection of models which can be rendered in the same page using <a href="http://underscorejs.org/#template" rel="nofollow ugc">Underscore.js</a> templates and the <a href="http://getbootstrap.com/" rel="nofollow ugc">Bootstrap</a> framework. 
You can view a working sample page using this plugin in single-page application mode at <a href="http://magentacuda.com/demo-of-search-widget-and-wp-rest-server-for-toolset-types/" rel="nofollow ugc">my portfolio website</a>.
<a href="https://alttypes.wordpress.com/#rest-api" rel="nofollow ugc">Version 2.0</a> implements an experimental <a href="http://v2.wp-api.org/" rel="nofollow ugc">WP REST API</a> server for Toolset Types custom post types and custom fields.
Please visit the <a href="http://alttypes.wordpress.com/search-types-custom-fields-widget/" rel="nofollow ugc">online documentation</a> for more details. This plugin works with Toolset Types 2.2.2 and requires at least PHP 5.4. <a href="https://wordpress.org/support/topic/incompatibility-between-my-plugin-and-wpml-multilingual" rel="ugc">This plugin is not compatible with the WordPress Multilingual Plugin by OnTheGoSystems.</a>

Search Widget and WP REST Server for Toolset Types

Search Types custom posts for posts that have user specified values for Types custom fields.

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.

Search Widget and WP REST Server for Toolset Types vs Rezerla Post List Field Search