Multibox: Expressions

[#1]

Hello,

If you refer to the below grid

My intention is to get a dynamic filter, if I select Business Grp as A then I should get filter of variable A which should show only A1

else I should get filter of variable B with only B2 value in the drop down.

I am trying to write an expression within a multibox :

If([Business Grp]='A',A='A1',B='B1')

I am getting -1 and 0 value in a filter drop down.

Does anybody has idea about it?

Kind Regards,

Varun