Hello,
Yes, you can have multiple instances of any Active Directory connection in the same form.
So, for example, user types in a search string into field1 and this calls the data connection FindUsersbyName1.
Then the user types in a search string into field2, and this calls the data connection FindUsersbyName2. And so on.
We have a Contact Selector XTP that is designed for a similar scenario. Not sure if this is what you need, though. Read thru this. Good luck!