For each player, you can click on the “Layout” button to split the displayed content to multiple zones.
On the layout popup, you can add zones, and define for each where exactly it will take place on the screen, using percentage.
Width - the width of the zone
Height - the height of the zone
Left - the distance from the left
Top - the distance from the top
Here is an example for a background with two zones, each showing a different playlist:
For each zone, choose one or multiple playlists.