There are team specific entities like game_team_etcetera but I think they only work in other mods, not CS.

One time I tried to make a map where one whole team could get killed by the other team destroying their 'voodoo dolls'. I had triggers at the spawns that set off a multithreaded, infinite loop of multi_managers. Then I tried to use a changetarget to redirect out of the loop later to another entity to do damage. I didn't quite get it to work but I might have been on to something...