There is no built-in functionality in RM to do that. As you know, device refers to the triggering event. The only way to do this is to make one conditional (in your actions) for each deivce, then build a string as desired based on that evaluation.
That being said, I did write a custom app that may do what you want, and there may be simlar options out there, too, if you don't mind using custom code. If you do want a rule, the first post in this thread has an example of the rule my app replaced: