What you would need to do is pull your current controller photograph the inside of each connector and the whole thing next to a ruler. Put it back. Then search images of 48V Bafang controllers that match the connectors including the one to the display. You may have some hidden functions inside the display that you can unlock. First look for images of Bafang displays. Find one that matches yours and find its model number. Then look for its Technical Manual. This will show you how to see each menu and how to move between them, changing individual settings such a speed limit and perhaps amps or wheel diameter. But the controller is the main controlling factor. Be conservative so you do not blow your motor.
I have a bike I told it's display that it has 100cm circumference wheels when it actually has 2200cm circumference wheels. I will leave it to you to figure out why.