If I reactivate my Facebook account and look through one of my old groups, will it show my name in the list of?

[The Doctor]

People who saw a particular post?
Thanks Pri, for the answer and I apologize for not be detailed.

What I meant was, if I reactivate, look through the group and then deactivate again, will my name be displayed in the list of people. For example for a post, will I be listed as one of the 'Seen by 10'

[pri✍]

If you mean by 'list' is members of a group, yes it will, of course as long as you're not removed as member of the group.
You can leave the group if you don't want to be seen as member.