I have addressed this issue in the past and I am still struggling with it.
I create assemblies to with parts in purely for positional purposes.
I create a layer which ghosts(grey) out what i do not require as to highlight what I am trying to show in my drawing.
There is some kind of bug that comes out to play sometimes!
In most instances I try to set the majority of the assembly to my "ghost"layer and it does not change all relatve parts , only a few.
restarting solidworks works sometimes but is not a reliable fix.
there are also way too many parts to click individually to change the layer( this doesnt work most of the time)
Please see below for your reference.
I require eveything to be ghosted excdpt the middle foundations.
The parts say they are in that layer but it does not propagate to the view