Similarly to how the Super Famicom (1990) was a further development of the Famicom, its controller is a further development of Nintendo’s familiar “D-pad and function buttons” approach. As games needed even more functions, the familiar A and B buttons were joined by X and Y, while the players’ index fingers operated the L and R buttons. The controller remained unchanged for the Super Nintendo variant that was sold in the West.
Nintendo patented the button layout, preventing others from copying it directly, but a similar group of four buttons can currently be found in practically all console controllers. The symbols and their order may vary, of course.