Roles and permissions

I think the solution depends a bit on two things:

1. How many people need this kind of access? Something like 10, or greater than 100? Basically, do you mind manually managing the category-level enrollment, or do you need an automated process?
   
2. What kind of access do they need? Similar to Student privileges or Teacher privileges?

For example, if it is just a few Teachers, then you could do something like "Assigning the teacher role category wide". You could potentially use that kind of workflow on a "Non-editing teacher" or "Student" role, but since those are not explicitly a part of that documentation, you may need to tweak a few extra capabilities on your own.

On the other hand, if it is a lot of students, you might be better off looking into Cohort sync. You can use CSVs & the Upload users feature to put people into Cohorts, but I believe that you still need to add the Cohort to the courses manually.

In between, the Category enrollment feature could also work for you, but there are warnings about possible server performance issues.

One way or the other, you may need to do some experimenting with editing capabilities/permissions, and possibly creating custom roles.