TIBCO Spotfire Configuration Blocks

I have a Spotfire analytic which has a drop down to show Quantity 1 and Quantity 2, however not all users are expected to see both options of the drop down, one set of users should see both the options of the drop down( Qty 1 & 2) , and one set should only see Quantity 1, I have created two 'mail groups' with required users in each of them, how can this be implemented in Spotfire ? Can Configuration blocks help ? Data is brought in via direct connection to Database ( no infolinks)