Possible to extend ObjectField or override the dialog to create custom asset picker?

I’m trying to find a solution to get over the problem at the ObjectField asset picker dialog, it list all of my object assets of the supplied type in a flat list. In my case the folder structure of the assets is important for identifying the right asset and a tree view and custom search behavior would be a much better option for my application.

Ideally I’d override the picker dialog with a custom editor window but I still want the asset drag and drop functionality.

Otherwise is there a way to build a custom editor Field that on the surface looks exact the same and can support the drag and drop behavior of an ObjectField while pulling up a custom dialog?

To do this, you’ll basically need to just create your own control, as it’s not really possible to modularly substitute one part of ObjectField. Luckily, this is all done in C# so you can dig into the UnityEditor dll and look at the code for how it’s done. The particular things you’ll probably want to look at are EditorGUI.DoObjectField() and the ObjectSelector class (which is just an EditorWindow).

Another way (then Adam-Mechtley proposed) described here Filtering an object field in Unity Editor Extension - Stack Overflow