You can copy any facet to another location in the Facets tree. Copying a facet to/from a shared catalog or category copies it to/from all shared locations. Copying a parent facet also moves its children. Copying a child facet does not affect its parents.
To copy a facet:
In a Merchandising project, navigate to Search Merchandising and show Facets.
In the Navigation pane, click the check box next to the facet that you want to copy.
Click the Duplicate icon.
In the Select Destination dialog, use the Search tab or the Browse tab to locate and select the facet where you want to nest the child facet. Click OK.