How do I filter parent options in admin.

I have a hierarchical custom post type. I need to be able to set parents for those post. All good and working so far. The problem is that there are hundreds of posts of this type and only a few that are actually candidates to be parents (based on the cpt-category). In the Parent field, the option list is unwieldy and I would like to filter it down to only posts that have the “parent” cpt-category.

Is there a way to filter this list. If not, is there a way to disable it so I can add my own?

I found a parent_edit_pre filter but I was unclear on what it does. It seems to only work with a selected parent id and therefore would offer no solution for me.

Thanks for any help you can provide.