Dave Bergschneider

Intuitive Category Checklist makes selecting categories easier for sites with a large amount of categories and sub-categorization. This plugin works in both quick edit mode and stand full post mode.
Related Links: <a href="http://www.crunchingpixels.com/portfolio/2011/07/intuitive-category-checklist/" title="Intuitive Category Checklist Plugin for WordPress at Truimage Productions" rel="nofollow ugc">Plugin Homepage</a>.
This release has been tested compatible with all WordPress versions since 3.1
Please submit feedback to the plugin’s home page in regards to features you would like to see in the future.
<h3>License</h3>
Good news, this plugin is free for everyone! Since it’s released under the GPL, you can use it free of charge on your personal or commercial blog. If you have found this plugin to be useful plese give it a rating or you can thank me and leave a <a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=39WPEFFWFDXTL" title="Donate with PayPal" rel="nofollow ugc">small donation</a> for the time I’ve spent writing and supporting this plugin.

Intuitive Category Checklist

Adds expanding/collapsing functionality to the categories checklist inside posts.

scribu

newvibe

Must use Classic Editor plugin – Add to my list of gripes with Gutenberg that it uses the REST API to display the categories, adding nothing to the categories box for the user while rendering the wp_terms_checklist_args filter useless. If you don’t already use the Classic Editor plugin (installed more than 5 million times to date), you’ll have to use it for this plugin to work. I’m looking for a work-around…
Does your list of categories go on and on, making it difficult to scroll to and find what you need? This plugin will collapse groups of subcategories into expandable submenus, which you may open and close as needed, cutting your category list down to a manageable size. Submenus with checked categories are not collapsed (but are collapsible), so you won’t have to hunt for them.
Thanks to scribu for the code from his Category Checklist Tree plugin, which prevents the breaking of the category list heirarchy.
This plugin works with post categories and WooCommerce product categories too. According to users, it works with custom taxonomies!
Links: <a href="https://www.newvibewebdesign.com/collapsible-categories-in-admin-for-wordpress/" rel="nofollow ugc">Plugin News</a> | <a href="http://newvibewebdesign.com" rel="nofollow ugc">Author’s Site</a>

Collapsible Categories in the Dashboard

In the Dashboard, collapses sub categories into hidden submenus that can be expanded and collapsed.  Keeps selected categories visible.

Intuitive Category Checklist vs Collapsible Categories in the Dashboard