Open the Select Expert in the report. If you have not already set a selection formula, select a field, any field. Once you have the Expert open, click on the formula button and enter something like this:
({table.User ID} = {?MyParameter} or {table. Client ID} = {?MyParameter} or {table.Order ID} = {?MyParameter})
Please note where I have places the parentheses at the beginning and end of this. These are required if you have any other selection criteria defined or you won't get the data you're looking for.
-Dell