When voting, display only dates already unanimously approved

When I arrive at a poll, I'd like to have a quick toggle filter that only displays dates that are already OK for all other participants.

For example, if the vote contains 30 dates, but for the moment only 7 dates are OK for all the others, I'd like to display only these 7 dates, to directly tell if I'm available on one or more of these 7 dates.

This filter would have no effect when you're the first participant, of course.