[ScriptUI] Two questions How to Create Button inside edittext? & Edittext object inside listbox?

I reckon this will be a rather complicated setup. ScriptUI isn't built for that kind of thing. For more flexible UI features you should be looking at CEP panels instead of ScriptUI.

I vaguely remeber an old, old post on this somewhere here on the forum. Perhaps you can find it with some patience. It's basically all a fake where you write your own code to get a dynamic text over a button and use your own graphics to insert custom symbols/ icons into otherwise text-based elements. None of this is supported out of the box AFAIK.

Mylenium