I don’t know of an easy way to do that in the Report’s parameter form. Lists of values from parameter form’s items don’t allow the use of bind variables (parameters) by default, and AFAIK you can’t change the LOV’s query at runtime.
However, there is a way to do it using the Reps_UTL.pll library, but I have never tested it. If you have access to My Oracle Support (formerly Metalink) see note 185951.1
If you are calling your report from a Forms application, you could do it creating as many record groups as needed, and changing the LOV’s record group in the first item’s when-validate trigger.