I just recently started learning Custom Post Types, but haven’t been able to find any documentation that would allow me (at least in the admin) to nest them.
My requirements are, a book post type with cover image (feature image) and description/summary (editor), and a chapter post type with chapter image (featured image), editor, excerpt
Both of these are easy, and really quick to accomplish, only hard part is I need them nested, so when you click into a book in the admin, you can see/edit the details, and add a chapter from there.
You can use the Posts 2 Posts plugin.