1 course that gets its enrolment from 4 other courses
X is a meta course and Courses 1, 2, 3, 4 can be normal courses with standard student enrolments. These courses can contain resources, and activities that are specific to those courses, but they may also only contain enrolments. Students enrolling in Courses 1 or 2, or 3 or 4, are automatically enrolled onto Meta course X when the course is associated as a child course to Meta course X. The meta course is dependent upon its enrolments from each of the non-meta courses, the child courses.
For example, a math teacher has 2 algebra and 2 geometry courses and wants a "home room" to place things of interest for all of their students. The teacher creates a meta course called "Teacher's home room" and links the algebra and geometry courses as the "child" courses.