one option,
you can use a parameter to help with this. If you make it numeric just allow for a 1 or 2, then add into the select expert what you want those two values to do.
something like:
({?param}=1 and datepart('d',{table.datefield})<16)
or
({?param}=2 and datepart('d',{table.datefield})>15)
Edited by DBlank - 23 Aug 2012 at 4:25am