trilobita

Editor Remit gives administrators fine-grained control over which categories editors and authors can work in. Assign permitted categories to a user and they will only see and edit content within those categories — nothing else.
Who is it for?
Organisations and agencies managing WordPress sites with multiple contributors across distinct content areas. Common examples:
<ul>
<li>A university with departments each managing their own news and pages</li>
<li>A company where different teams own different sections of the site</li>
<li>An agency managing a client site with multiple editors who should not have access to each other’s content</li>
</ul>
How it works
Once a user has permitted categories assigned, Remit:
<ul>
<li>Filters the post and page list screens to show only content in their permitted categories</li>
<li>Restricts the category selector in the block editor to their permitted categories only</li>
<li>Blocks any attempt to save content outside their permitted categories — enforced server-side, not just in the UI</li>
<li>Allows access to uncategorised content (posts or pages with no categories assigned) so nothing is inadvertently locked away</li>
</ul>
Restrictions apply to users with the Editor or Author role only. Administrators are always unrestricted.
If a user has no categories assigned, no restriction is applied — they behave as normal.
Page support
By default WordPress does not enable categories for pages. Editor Remit includes an optional setting to add category support to pages and apply the same restrictions there too. Enable it under Settings > Editor Remit.
Block editor (Gutenberg) support
Remit works fully with the block editor. The category panel is filtered in real time to show only permitted categories. Saves are validated server-side via the REST API.
Lean and focused
Remit does one thing well. It does not touch custom post types, custom taxonomies, tags, or any other content type. There are no complex role matrices, capability editors, or access control lists to configure.
Current limitations
Remit restricts posts and optionally pages only. Custom post types, custom taxonomies, and multisite installations are not currently supported.

Trilobita Editor Remit

Restrict editors and authors to specific categories for posts, and optionally pages. Simple, focused, no bloat.

Rapidweb

Edit user permissions for Ninja Forms.
By default, all Ninja Forms options are only available to users with the ‘Administrator’ role. This plugin will enable you to set which elements of Ninja Forms different user roles should have access to.

Trilobita Editor Remit vs Permissions Editor for Ninja Forms