is it possible to create a hierarchical dimension on Jasper Report Server for use with the ad-hoc report builder

I would like to create a hierarchical category (like Country -> State -> Suburb) that a user can use when building reports (using Report Server Ad Hoc report builder).  Is this possible?

I know that the user can manually drag in country then state then suburb but it would be convenient just to have 1 dimension.  This would ideally then deal with drill downs in charts (is this being too optimistic?)