Press and hold the "Home" button for 3 seconds to enter the controller menu, then select "Settings"→"Button".
Macro customization
M1/M2/M3/M4 can be programmed to different key combinations. They can also just map a button.
Button mapping and Turbo function
A/B/X/Y/LB/LT/RB/RT support mapping and Turbo function.
How to Set up Macro Function
How to Set up Button Mapping & Turbo