The only thing that comes to mind would be if you spawn those objectives at each map start via an in-game admin command such as !spawn objective (or something of the sort, depending on how you bind your admin command to the object to be spawned). The objectives would have different coordinates that have been set and determined before hand and depending on where you want the objective to spawn, you run the appropriate command for it (for example, !kitchen would spawn the kitchen objective).
As you may have guessed the downfall with that would be that you would have to type the command every time the map starts, i.e. its not automatic. To make this automatic then I guess you can just make a new CON file somewhere in your Settings folder and type in the appropriate code, however I have no idea how the game would know how to spawn a different objective each round.
Maybe you can make a conditional statement that runs objective A when the map round number is odd and objective B when it is even? Just a bunch of ideas lol sorry for the novel here.