Here is the resulting file with some explanations:
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Only the topmost object is selected for duplication. All other are deselected. Some more clicks that a simple "No" but actually allows for more flexibility. For example you can create a copy that has one of the openings with slightly bigger opening ore another shape, ...
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Here is the resulting tree. Of course subelements are shown under both AllWall objects because they both depend on them. But that does not mean that they are duplicated. For example both marked topfloor elements in the tree are actually one object.
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Dependency graph shows that only the topmost object is duplicated (as selected) and it depends on the same non duplicated objects. Hope that makes sense now.