Sure - A Composite Hierarchy is where you have 2 lists that make up one list
So, a list called L1 Country is the parent of a list called L2 Cities
The advantage of this structure is you can model at the L1 level as appropriate
If you are getting the error on the first level, then the same description must exist for different items.
If that is what you want they as @PavanKumar mentioned, you can use a numbered list to display the same description, but try an use a code in all cases if possible; it is much easier later on if you have a code!!