If so, it depends on how you make them. Is it just a panel? You can make a filler from a standard cabinet. Just start with a standard cabinet and, in construction settings, remove everything but the back. Now resize the "cabinet" to whatever size you need for the filler and add it to your room layout.
Is there a way to add filler strips like this that do not get cut . I don't want these skinny strips showing up in my nest as I make them from scraps
and size on site .
I find that if you are nesting make a material that has the dimensions of 1mmx1mm, then when you go to nest, it can't use that piece cos it's too big and will delete it from the cutting list altogether and you won't have to ignore it. I tried making a material called "do not cut", but guess what, it created too many problems on the floor:)