Hello-
New user here. I’m building a house. I made a slab, grouped it, and assigned it to a new “SLAB” layer. I then copied the slab group, assigned that to a new “WALLS” layer (because I wanted to use one of its surfaces to run the Offset cmd to make my 4" thick walls). I exploded the copied slab geometry, dumped everything but the top surface, ran the Offset on that remaining surface, then Push-Pulled my 8’ high walls. I then grouped just the walls, and assigned the group to the Walls layer. When I uncheck “Visible” for the Walls layer, the walls hide like they should. But, when I uncheck “Visible” for the Slab layer, both the slab AND the walls hide, leaving me with a black outline of the walls(!) Why are my walls hiding, when I’m only hiding the slab? I double checked the layer assignments under the 'Entity Info" window, and it says the elements are in fact on the correct layers I assigned. Any clues? Thanx-
Make sure that you make all of your geometry on Layer0 [ALWAYS leave it as the current Layer], then select that geometry and group/component it and assign other layer to that ‘container’.
So far so good - you seem to be doing this good practice…
The rub comes when you explode a group/component-instance !
Any resultant geometry is put onto the Layer of the ‘container’.
This is a well known issue, and it has been requested that SketchUp addresses this…
But thus far… nothing.
However, I wrote a tool…
Which works in the background.
It suggests you might NOT want to reset the current layer away from Layer0 - but you are not stopped !
It also lets you explode selected containers onto Layer0, even when the original containers are assigned another layer.
Also any new geometry you add is assigned Layer0 - irrespective of the current-layer.
It also has a tool to reassign Layer0 to any selected geometry [ containers are ignored, optionally geometry in an selected containers can also be reassigned ]…
PS:
If you are not a member at SketchUcation [and why aren’t you ?], then you can sign-up for a free account - although there is an inexpensive Premium membership - which helps support its continued existence - which offers many benefits - discounts, freebies components/styles/materials, free-draws, kudos etc
Thanks for the info. Makes sense. Coming from a background of Rhino, I see a lot in Sketchup that seem a tad illogical. Just my opinion, of course 
Thanks-