Formula for groups?

I need a formula that would read something like this:

I have 2 Groups. First group is called @Books and second is called @Numbers. @Books is in 'details a'.Second group "@Numbers" ranging from 1-12 is the 'details b'

I now need a true/false formula that would read .. if my search parameters {?SearchNumber} = 12 in @Numbers then @Books is true, else false.

How can I write a formula like that??