How to display "similar items" from the CMS?

I have a CMS-based site in which I need to display “similar items” when a user is viewing an item page. It is not an e-commerce site, but this is very much like a “related products” feature.

Lets say I’m looking at a Course page, for a course in the School of Psychology. I want to show other courses that are also in the School of Pschology.

This sounds like it should be very straightforward,

  1. Setup CMS collection “Courses”
  2. Design that CMS Collection Page, adding a Collection List to it
  3. Bind that Collection List to “Courses” as well
  4. Filter it to only show items that match the current Course’s “School”

However the Filter isn’t showing any dynamic options, only static ones. I could hard code it to “Psychology” but then you’d get a list of Psychology courses on a “Contemporary Dance” page too.

Here is my site Read-Only: LINK
(how to share your site Read-Only link)