I don't understand your question, do you wqnt to make a pose set that works for couple of people (sort of group poses) or do you want to pose multiple people at once for making a photo/ screen capture...
the answer is yes for both though...
there are some poses out there that automatically pose the sims on the right position for a pair of couple or friends poses
if you ask if it is possible to pose multiple sims at once, then obviously yes...