Create other roles

Is it possible to create a rule or permission or overwrite existing ones?

In my project, I do not want a business user to have access to the source file browser for the repository, this is an example.

The [1] documentation only shows the roles:

Guest
Reporter
Developer
Master
Owner
[1] doc/user/permissions.md · master · GitLab.org / GitLab FOSS · GitLab