Based on Moodle Custom Course Fields and JS. It based on default moodle course page, but extend it to simple course filter. URL: /course/
1. Add a Course custom fields
Define additional fields that can be used for filtering courses. This allows for a more tailored search experience based on user-defined parameters.
Site administration → Courses → Course custom fields
You can choose from several field types: checkbox, dropdown menu, number, short text, or textarea.