Hi Leo,
The other option is possible with normal RDBMS is using combined query.
But am not sure if this is possible with BICS.
create 2 dummy objects in universe as Dim1, Dim2 as strings
Create combined query as
select Dim1,ActualDimension1, ....from table
union
select Dim2,ActualDimension2, ....from table
Use this Dummy object as input control which filters the corresponding dimension values in the table