what I mean this person share video in this group, is there anyway to find beside this group , which group he/she also sharing the post to? If you know what I mean here.
Not sure about videos but with images you can find other places it's used. You sound a bit stalkerish though.
but if you're cyber stalking you don't know what those groups are. Do you have any answers for the OP?
If you know the post's content, you can do a Google search to see if it has been shared on other websites or social media platforms. This can help you track down the person who shared the post originally.