Ah yes, I see. Those 2 techniques of breaking a scene apart – first by layers, then by light groups – won’t combine with each other.
In your case, to add the emission pass back over, you would activate the emission pass on its own layer, then Add it over one of those recombined scenes, either the layer nodes OR the light group nodes.
You definitely can use light groups and layers together, but keep in mind that’s going to get complicated quickly, which is why it’s not something I covered in a fundamentals course. Basically, you would set up the layers, and THEN the light groups per layer. If you do that for every layer, you can see now you’ve got a LOT of layers and passes to put back together. But you will have amazing control, hahaha!
