The Model level itselfs act as the highest Parent level.
Consider a component as a mini-SketchUp file…
When you have a model, you are actually in a component.
The thing is, DC won’t display the model attributes through the panels, allthough they can have them (but it is a bit cumbersome to set them, since you have to import the model in a new file, set the attributes in the DC panel, save it and open again)
Instead:
Make dummy components (I sometimes just draw a recrangle and make it a component). Set the attributes for the glob al settings, do not nest them in the existing, but put them somewhere in the model. Name it GlobalComponent or simular.
Refer to them in the existing components.
You need to redraw when you make a change in the global component, however.
Refer in the existing components to GlobalComponent!MaterialSetting etc.
Also see this thread: