use the camera viewport in order to do that. if you have camera1 and camera2, which you want to show different things from each one, on two parts of the screen:
CameraViewport camera1,x1,y1,width1,height1
CameraViewport camera2,x2,y2,width2,height2
CameraViewport camera1,x1,y1,width1,height1
CameraViewport camera2,x2,y2,width2,height2