Methodology for linking Data Types and filtering Repeating Groups

My site will be composed of several interlinked tables and will use repeating groups heavily to pass data and filter data within other groups and pages.

I’m struggling to find a solution that works other than passing the Unique ID into the URL to filter a group on a second page (or even the same page). I need human-readable URLs and it’s proving impossible to get working. Surely I’m missing something obvious here right?

My simplified database example looks like this

Data Type: Courses
Title: Text
Category: Categories

Data Type: Categories
Name: Text

Page 1 contains an RG displaying all categories.
Type of content = Categories
Data Source = Do a search for Categories
Cell text = Current cell’s Category’s name

On click, trigger workflow to send additional parameters to page 2

URL looks perfect

URL Path

Page 2 contains an RG displaying all courses
Type of content = Courses
Data Source = Do a search for Courses

Conditional = Get ‘Cat’ from URL when not empty

Next, I need to get the same data source for my courses ‘but’ I need to filter the results by the category matched in the URL

I know from research that this will never work because Bubble is looking for the Data Type 'Category’s Unique ID and not the Name of the category which I am passing through in the URL.

I have done countless research and watched hours of videos to try and understand about the data type relationship and I can’t find any solution to using the URL value to filter my Repeating group.

I’ve tried using the filter method which I can’t get to work.

Filtered courses

I’ve also looked into using Grouping but I can’t get that to work either.

Put simply, I need to filter my repeating group of courses by the category name which is stored in the URL in human-readable format (not Unique ID). I cannot find a solution to pass over the URL text value in a way that the RG will accept it as a method of filtering the results of a different table.

Many thanks in advance for your help and support with this.