Input Controls Designing in UE

In Java, for example, If I want to create a Button component I should code a class for that. I just attached an image with basic Input controls and what I want to know is in Unreal Engine, If I want to create components like Button, Drop Down Menu, etc. I probably should code to make it functional. But for the designing part of that component should need coding in Unreal Engine? Appreciate the answers. Thank you.

Yes, Slate and effectively UMG that using is use stacking layout UI, similar to Android, you got widgets which can compose child widgets, laying them out.

So you can create SCompoundWidget class in Slate or Widget Blueprint and you can reuse that widget elsewhere, so you can create UI that looks a button and reuse it, in fact you force to do that in case of listing widgets

You can read it here: Slate User Interface Programming Framework for Unreal Engine | Unreal Engine 5.1 Documentation