How to select all single values in the header area

Dear Experts

I got a request that the user wants to select a single value or all single values in the header area. E.g. if the values from characteristic master data are A, B, C and D, the selection can be one of these values or all of them. With the standard BPS configuration, due to the unique combination in the header area, selection of 'All' single values is not possible. Is there a way to select all single values in the header area?

Thanks, Jessica