Welcome to the forum.
You are asking about record access privileges that would be set under Accoutns&Privileges.
Here's a post with an example of someone else doing the same type of thing.
The FMP help index gives a good example of what you are trying to do...check it out.
You will have to have a way of "tagging" the records or determining some criteria upon which the person's privileges may be calculated (like Field1 < 3, or Field2 = Get(AccountName), or the like)
That's precisely what I'm looking for.
Thank you so much.