Editor GUI Like mesh import animation inspector

Hi, I need to create a GUI to edit a list of objects. I have a class AClass with List objects, and the objects have their attributes and a list that I want to edit with the ReorderableList function (so, i think, I shold use a Custom Editor).

So, my idea is to show a custom editor of AClass, let choose the MyObject I want to edit and show below its custom editor.

The reference should be the mesh import -> animation tab inspector: You can select the clip, then you can edit it in the interface below.

So now I can show the "Clips", how can I say "Show the custom editor of object X here"?

Thank you in advance