Working with virtual catalogs considers creating linked categories. A linked category is a category in a virtual catalog that is inherited from a common catalog. The inherited category contains links to all of the items in the source category in the common catalog. Moreover, all product attributes are inherited with each item.
To create a linked category, right-click on a virtual catalog (or a category inside virtual catalog) in your catalog tree and select "Create Linked Category" option from the context menu:
Now use search tools on the left to find a category. Select required linked category from the list and finish creating a linked category.