On the go I listening is different than at home. When traveling I only want to hear my favorite tracks and not full albums. The function to do that is in Roon but not in the ARC App. I have seen that request so often in this forum. Please put it on your list (soon!!!)
Do you mean to just transfer favourites to Arc or to filter just favourites once downloaded to Arc?
You can do this in Roon Arc,
Go to library —> tracks —> press the heart