The menu options in WP already have support for created native posts types, and custom post types, and existing taxonomies.
But in my plugin I provide a couple custom URLs that are not associated with any post object. E.g.
domain.com/open-entries will list all the entries for a particular CPT with certain values set in postmeta; and other staff like that.
I can tell my users to add links to this urls using the "Links" part of the menu administration, but would require for them to remember and enter the links manually, which is not ideal.
Ideally I would like to have something like this:
Where "Custom Links" is another foldable panel where to insert my custom links, so it's easier to insert them into the selected menu.
Where should I begin? What filter or action is there to hook into?
Thanks and regards.