How many availability groups can you have on the Primary server?

In the real world, you may have one or more associated databases that would be required to fail over as a group but that doesn't mean adding all the databases to the one group and failing them all. This is where I get a bit confused. So, can you have more than one group, on the one server, on the one WSFC node?

I am designing a possible SQL 2012 HA & DR within an WSFC and am worried about the above questions...see attachment for architecture