I'm new to Godot so not sure if there's a function to do this but if you do this:
var list = InputMap.get_action_list("ui_accept")
for k in list:
print(k)
You get all the keys (or other inputs) associated with that particular action so it would be easy to build a dictionary of these values with their key (or button) names... provided you can find a list of them somewhere :smile: