As far as I understand, your rule for such URLs would be to check URLs with "collections", but without "products".
There's a topic discussing regex for excluding string pattern. However, I think it's not supported in Google Analytics.
One approach would be two use two filters in your reports: one to include all pages with "collections", an other one to exclude pages with "products". You can of course bee more specic with the rules. E.g.
![enter image description here]()
If for any reason you must use only one filter, you could craft something like this, meaning: get all pages starting with /collections, having some other letters (collection name) after an other / character, which is then followed by URL parameters (?) or end of string ($), meaning no product names can come after.
^\/collections\/[a-z]+(\?|$)