You can assign say a LPF filter to a whole program which you can modulate frequency using a qlink during a live performance.
First you need to add a LPF on the program you need it on. Say insert 3.
You need to go in qlink edit mode, hit the āprojectā tab (bottom left).
Once you land on that page, from top to bottom, select āprogramā, then insert 3, then select the fx parameter you will want whichever qlink to control (here frequency) and you should be good to go.
That qlink, in that project, will always be controlling the frequency of your LPF for this program.
Check this video where this dude explains it at 4:18, except that he assigns a qlink to a fx parameter which will control a submix instead of a program. So the only difference is that when he choses āsubmixā you need to chose āprogramā:
https://youtu.be/d1UWKRHLaZI
Hope this helps!!