Okay yeah you don't need the advanced UI to do that.
in the normal controller config window, click the X button. Bind it to the controller button you want.
Then, click the left trigger button, bind it to the same controller button. It'll work just fine.
in the normal controller config window, click the X button. Bind it to the controller button you want.
Then, click the left trigger button, bind it to the same controller button. It'll work just fine.