Buttons in dropdown

Its been like 4th hour of me just searching for a way to add buttons under dropdown, but still nothing.
I tryed to get some scripts from internet, that caused my project to crash (Literaly, the whole project, had to make new one and copy everything). Tyed to just put it under dropdown, which would just make sense, but that doesnt work, tryed to edit the Template, which appears in dropdown, the dropdown stops working etc. I got no clue what to do…
I have buttons, but i need to get those buttons appear in dropdown.

Just add it under Template → Viewport → Content → Item and delete the default Item checkmark and label.