Hi parsiantd,
In K2 you can't do that... but into joomla users.. you can select 1,2,3,.....X "Joomla groups"..
But K2 you can create any users_group as you wish..
so you can build 4 .. 5 group witch different access Combinaison.
maybe it is a best solution for you ?
Best Regards,
Emond, Jean-Philippe