How to override a record rule.

Projects are visible to users who are added as team members based on rule. How to use a function to remove this  record rule.

Example:

Project A: Project Manager - Administrator, Team Members : User 1 and User 2.

Both users will be able to see the projects.

Now how to override this record rule so that the user's cannot see the project. Need this using a function instead of creating a group and manually adding the rule.