Richard Vencu

This plugin creates and maintains one or multiple hierarchies of blogs in the WPMS network. Options screens appear in network admin dashboard. The blogs hierarchy can be used for several purposes such as:
<ol>
<li>consolidate posts (or latest posts) from descendant blogs only</li>
<li>display a list of descendant blogs or even a tree of blogs from any node</li>
</ol>
Other features
<ol>
<li>Hierarchy cannot loop (cannot set as parent one of the descendants or itself)</li>
<li>The main site (blog_id 1) cannot have a parent</li>
<li>Individual blogs may be taken out of hierarchy</li>
<li>Multiple independent hierarchies may be created 
Limitations: this plugin is not optimized for large installations. More than 50 blogs can be hard to manage.</li>
</ol>

Network Sites Hierarchy

This plugin creates and maintains one or multiple hierarchies of blogs in the WPMS network.

Amit Sonkhiya

K.K.Agarwal

Gutenberg Editor already maintains the parent-child relationship when you select a category. So the child doesn’t move at the top in the category meta box. So this plugin isn’t required if you’re using the Gutenberg Editor.
Categories in Hierarchical Order plugin applies to WordPress Classic Post Editor only.
This plugin contains functionality to let you maintain default hierarchical order of categories when you select and save them for a post in your WordPress Admin Classic Post Editor.
The selected category/categories, to which a post belongs, are by default pushed at the top in the Category tab while saving the post. Whereas activating Categories in Hierarchical Order plugin will keep the position of selected category/categories unchanged as per their parent/child relationship.
For support, use support page available here or visit <a href="https://www.astech.solutions/wordpress-javascript-jquery-plugins/categories-hierarchical-order/" rel="nofollow ugc">the page</a> at our official website. A <a href="https://github.com/as-tx/categories-hierarchical-order" rel="nofollow ugc">GitHub repo</a> is also there to post issues, contribution and feature requests.

Categories in Hierarchical Order

Does exactly what you expect from this plugin. Nice!

Works great!

Does exactly what should be the default option in Wordpress, great! Sorely needed if you have many categories (possibly with very similar names) and rely on a complex hierarchy.

Great!

Perfect

Why is this not part of the WordPress core yet? This plugin fixed my ugly looking category structure! Thanks guys!

Brilliant!

Categories in Hierarchical Order plugin maintains the hierarchical order of categories list in the Category tab under your WordPress Admin Post Editor …

Network Sites Hierarchy vs Categories in Hierarchical Order