This feature has been around in the desktop and tablet apps pretty much forever, but we only recently brought it to the web app. If you're editing a student, you can now easily navigate to a list of all that student's COEs. There's a link "List COEs for Student" just below the Student ID Search box here:

When you do that, you'll be taken back to the Search page and shown all COEs the student has appeared on:

As with almost all the links in the web app, you can also right-click on the link and select "Open link in new tab" so you don't lose your place on the current student:

This got added just a month or so ago. If you don't see it yet, it will be in your next release.