Associate multiple Profile2 profiles with vocabulary and expose the vocabulary's terms in a views' filter
This probably doesn't answer your specific question, but this poses an alternate solution.

If you created two fields to allow the user to select a different number of terms, you could potentially do this with one field and a form_alter hook or validation.  

The idea is that the form alter would change the number of allowed values based on some custom logic. Ideally this would make downstream functionality like views simpler because you're dealing with a single field.

The answer on this question may help give you ideas.
How do I set the fixed amount of values to 11?