Tap [OUTPUT] at the top of the screen to display the video output. Tap [INPUT] to finish.
Select any of the 4 displays and drag diagonally from the corner of the display to expand the display. When an expanded display is active, 1-4 will be displayed on the top left on the display, use 1-4 to switch between the different displays.
To close the expanded display view, drag diagonally from the corner to the centre of the display.