If you need to have archive then using fields in a field group may not be the best way. I would look at the possibility of setting up a custom post type for courses and adding a taxonomy for years or semesters and somehow creating a relationship between the teachers and courses. I’m sure it’s a lot more complicated assuming that multiple teachers have access to the same courses. You may need a custom post type for semesters, but I can’t say how all this would work together.
At any rate, there isn’t any real way to “archive” the values in a field, at least none that I know of.
