In order to understand the wiring, you need to describe the throttle functionality. Did your old throttle have a display to indicate battery voltage? Does the new one have display plus on/off switch?
A simple thumb throttle only needs three wires, +5V power, throttle signal, and ground, So you should describe what else the old throttle did.
As you add functions, you add wires. If the new throttle has functions not present on the old one, you can ignore them and don;t connect, Otherwise, you have to identify wires on the controller to support them. and complicate life by wiring them up,