Thank you all!!!
Incredible how you guys respond...
@Gilles: Will take a look at it today. Thanks.
@Box: Very helpfull, will take a look at what you mentioned: "You probably need to learn how the inferencing system works and how components separate and allow you to repeat geometry." I'll try and find some tutorials on the inferencing system...
@pbacot: By a layer I meant just one part of the closet, for examle one side...
I'll let you alle know how I proceed using all advices...
Again, thanks!