Re: Pages Report
I solved this one. Instead of filtering for the URL-parameters as they appear in the browser (e.g. groups%5B0%5D), which does not work, I now filter for the “translated” parameters (e.g. groups[0]). And it works as advertised. No regular expressions needed.
Re: Capture multiple parameters in Custom Dimensions
We are evaluating several avenues. If and when we find a suitable solution, I will post it here.
Thank you @heurteph-ei for your help. Very helpful and much appreciated!