Playing Director
Get as many people up for a scene as feels appropriate. Designate one as person as the "director".
The performers (including the director) will improvise a scene (or multiple connected scenes) like they normally would. In fact, everyone should treat this like the beginning of a run. The only person who will have a different relationship to this exercise is the director. They will be allowed to pause the scene and give direction to other performers for a specified number of times (ex. "You can stop the scene and ask a performer to do something different three times.").
The goal of this exercise is not necessarily for the director to learn how to teach improv or to improve the scene in any sort of "objective" way. The goal is for the director to simply notice what would improve the scene in their opinion, and thereby learn something about their taste in improv and stories. If they give direction that seems to not work out like they wanted or imagined it, then that can be food for thought too.
With all of this in mind, it should be important for the non-director performers to be good teammates and give their best effort at following direction, even if it feels at odds with what they would prefer to do on their own. As a side benefit, the non-director performers may learn something about the taste of other people in their ensemble, which may inform how they improvise alongside each other in the future.