scribu

On the post editing screen, after saving a post, you will notice that the checked categories are displayed on top, breaking the category hierarchy. This plugin removes that “feature”.
Additionally, it automatically scrolls to the first checked category.
Works with custom taxonomies too.
Links: <a href="http://scribu.net/wordpress/category-checklist-tree" rel="nofollow ugc">Plugin News</a> | <a href="http://scribu.net" rel="nofollow ugc">Author’s Site</a>

Category Checklist Tree

Simple and without configuration, it's just does what it says it does.



Works as expected

Really, I just can't understand why WordPress developers walk another way - this is, how it should be! :)
I have launched over 100 websites on WordPress - and they all have this plugin.
Thanks again!

Thanks!

Preserves the category hierarchy on the post editing screen

Amin Nazemi

This plugin disables Pagination in navigation menu lists and preserves taxonomy hierarchy. 
Also, it helps you when you using WooCommerce and you have more than 50 category items. 
It can preserve WooCommerce category hierarchy.
FEATURES
<ul>
<li>Disable Pagination in nav menu add item lists </li>
<li>Preserve hierarchy in category nav menu add item list and posts category selector</li>
<li>Automatically scroll to first checked item in post category selector </li>
<li>Preserve WooCommerce category hierarchy</li>
</ul>

Preserve Taxonomy Hierarchy

Preserve hierarchy in posts category and navigation menu editor lists.

Category Checklist Tree vs Preserve Taxonomy Hierarchy