Quick question re FoxEE

Can someone explain how the Member group assignment in FoxEE/FoxyCart works?

Basically I need to assign a Member to a group when they buy something just like in Simple Commerce but need to have multiple groups like so:

1) Customer 1 buys item A - goes into Member Group A 2) Customer 1 buys item B - goes into Member Group A and Member Group B….etc…

Is this how it works?