What is the best practice for DDAU components?

The easiest way to explain what I mean is by example. Suppose you have an array of Ember Data records that represent students, and a number of components that are meant to represent classes. How would you make those components sensitive to changes in the belongsTo relationship of the students? I’ve tried just having a computed array within each component that filters to see if the student is in the class, but it doesn’t seems to work because the component doesn’t rerender when the computed property changes (because the attrs didn’t technically change.

My current version directly mutates all the components via a service, but this is obviously unnecessary complexity.