Elevating Tickets

You likely want to create an action rule that triggers on the update which should be triggered by the escalation and has criteria that matches the escalation level(plus any other criteria to make it specific enough for those particular tickets and so it doesn't have a chance to get stuck in a logic loop).  You would then set the action to change assignment to the alternate tech group.  I haven't tested it to confirm it would work 100%, but the logic seems reasonable that it can and it should point you in the right direction on how to handle it if my suggestion doesn't get there already.