The CrossView function can be used to access content currently being used by the RSE system on the opposite side of the car.
To access the CrossView function, press the

or

function button, dependent on the side of the RSE system currently selected. The content being used on the opposite side of the RSE system will be played through both sides of the RSE system.
Whilst the CrossView function is active, the RSE system that activated CrossView will be controlled by the RSE system on the opposite system of the car.