1 layout for 20 displays, each display with different calendar

To be completed by the original poster:

CMS Version

Docker 4.0.11

Player Type

WebOS

Player Version

R404

Issue

I have 20 Displays, and I have a layaout with calendar, but each display show its own calendar. How can I set a variable on each display that I can use in layout? Something like {ics}. I mean a parameter unique in displays that you can use in layouts.