How can I limit roles to only see the information within that role?

We have our operations roles, which vary from wide access to limited, and sales roles that can see all but only edit their own forms, and then outside sales reps that can only see and edit things that they create. All of those work exactly as intended, what I am trying to do now is create a subset of our Outside Sales Rep role that instead of only being able to read and edit their files, they can read and edit any files created by a member of the new role, we can call it OSR (State) for short.

I could see how I could do it with a field within the table that sets a project under the subset, but that allows for far to much human error. Is there a way to do it simply with permissions?