The connection for the nissan pathfinder check the following image

The unit is compatible with factory backup camera.

If connect to the aftermarket camera, check link below: 

If still want to make the factory backup camera to work then need to do the wiring.

find the yellow arrow point connector and find the factory backup camera CVBS and Ground Wire. split the wire to the following position wire.

For the steering wheel control, this unit is not go through the canbus, check following video to learn for the steering wheel control.