Adding/Changing Functionality of Custom Post Type Main Admin Page

Question

I've created a custom post_type plugin. I would like to add a custom filter to the main list page that is displayed when you first click on the menu item in the left-hand menu (see image). But, I can not find the code that makes this list or how I can create my own code to replace the default page.

Also, I would like to add functionality to the delete (either individual post or bulk action). I want the post to be deleted, but I also want to delete the Gravity Form Entry for this post.

I've searched so many sites that I'm starting to confuse myself! :) Any help would be appreciated!

Answer 1

Don't have the direct answer myself, partially because I don't know what you want to filter for. But did you check how some of the plugins do it? Here are two examples: Filter page by template, Parent page filter.

As for your second question, not sure if that's possible. That also depends on how you have connected the form to the custom post type. You might have more luck creating separate questions and add more details.