You can find the metrics for each video in your groups media in Grytics or in the post list. Each video will appear as a single post with its interaction. For the post itself (that contains all the videos), metrics will be reflected in the posts list.
There is no detailed metrics about videos on Workplace at the moment.
Yes, you can export the list of people who have seen a post and also who haven't seen a post. To do this, go to Content Metrics > Posts List. In the "Actions" column, click on the "..." and select the export you want:
- Viewers for the list of people who viewed the post,
- Non-viewers for people who haven't seen the post.