You can use a * to grab everything in your scene in one collection, lets refer to that as CollectionA. Then lay down a collection node after that one in the chain with your 1 selection, CollectionB. With MRG last node wins. So set a modifier to turn CollectionA off. Then lay another modifier after that to set CollectionB to visible.
That being said you can also use Actor tags, visibiliity layer, outliner folder, etc… You have many options beside individual actor selections.
In case you have not found this yet: