kinggreene
if you map your controller buttons in the menu (Controller Settings, Configure A Controller) the scheme, which is then queried, is based on a SNES controller with action buttons in diamond shape, where the north button (top) is X, east button (right) is A, south button (down) is B and west button (left) is Y
if you are using a gamepad, where the buttons are organized in another way, this could lead to irritations.
see the picture on this batocera wiki page:
https://wiki.batocera.org/configure_a_controller
for switching A and B in the EmulationStation Menu, you can do this easily by going into System Settings, Developer and then activate “Switch A/B Buttons in Emulationstation”