Maria Daniel Deepak

WP Categories Metabox Extended extends the Category metabox on your WordPress editor. Once installed the Category metabox gets a search bar with which you search Categories. Also, this is only seen on “Add New Post” screen in the WordPress Admin dashboard.
From <a href="https://wordpress.org/support/wordpress-version/version-5-0/" rel="ugc">WordPress 5.0</a>, the search bar is included with the Categories metabox. In case you choose to use the Classic editor by using plugins like <a href="https://wordpress.org/plugins/disable-gutenberg/" rel="ugc">Disable Gutenberg</a>, then WP Categories Metabox Extended plugin will continue to extend the Categories metabox for the default “Post” post type.

WP Categories Metabox Extended

WP Categories Metabox Extended plugin allows you to search and assign Categories to your post in your WordPress editor.

devgirl

Creates a search page where you can use a search filter to go over a selection of your posts to search by multiple categories and tags.
<ul>
<li>You should have 2 parent categories with sub categories in both. </li>
<li>You should also set up some post tags. This will help you to really make full use of the plugin. </li>
<li>In your WordPress dashboard, go into Settings -> Cyba Advanced Search to choose your options. Use the shortcode: [cyba-advanced-search] on any page to show the plugin in action.</li>
</ul>
I definitely plan to develop this plugin further.

Cyba Advanced Search

Create a mini directory on any post or page with a filtering search function in a sidebar. Filters 2 top level categories of your choise and tags.

WP Categories Metabox Extended vs Cyba Advanced Search