Assign Gamepad Button To Widget Button

i was surprised to see that i can navigate and press widget buttons with my gamepad, out of the box. currently i have to press A on my xbox controller, to trigger a widget button. is there a way to assign a gamepad button to a specific widget button? i want one widget button to get triggered, when i press X on my controller, and another widget button when i press B.

another thing i would like to know is, when you reach the bottom most widget button and press down on your gamepad again, nothing happens. how can i make the navigation start from the top again?

your help is much appreciated.