I think what Freya is wishing for is different from what Layer Combinations do.
Layer Combinations simply store the state of all layers (visibility, locking, etc.).
I think what Freya means is instead of specifying in the Schedule Criteria, e.g.,:
(Layer = "Layer 1" OR
Layer = "Layer 2" OR
Layer = "Layer 3")
You could set
Layer = <a specific Layer Folder>
Let us say, Layer 1, Layer 2, and Layer 3 are all in the Layer Folder called "Walls"
Then specifying
Layer = "Walls"
would mean that elements on any Layer within that folder would satisfy the criteria.
This could be useful when you have to specify many Layers in the Schedule Criteria.
@Freya, Please correct me if I am wrong in my assumption. Also, could you clarify what you mean by hiding elements of any of those Layers in a Layer folder in the context of Schedules? By "hiding" do you mean not displaying them in the Schedule?
Also, this rule would encompass newly added layers, which are not automatically added to a layer combination. Adding a layer to a layer combination automatically based on its parent folder is actually my wish from a little while ago.
@Laszlo Nagy that's what I meant, indeed. I know you can work with layer combinations, but it's not as easy as using the folder. Like @GG_rakurs says, if you add a layer to the folder, it's automatically added. And you don't have to make different layer combinations just to make the schedule you want.