Greetings @suesf7
I am making an assumption that you are a student. If so, these two guides should help you in posting a video to a discussion.
How do I attach a file to a discussion reply as a student?
https://community.canvaslms.com/docs/DOC-10501-4212190728
As for your question about sharing a video from your group to facebook - there is not a direct feature that allows that in Canvas. And you'll probably want to make sure that is ok with your group members and your instructor before you download it and then upload it to social media! Just always nice to check in with people in case they don't want to be posted.
This discussion post is outdated and has been archived. Please use the Community question forums and official documentation for the most current and accurate information.