There's plenty of resources that outline how URLs should be organized for RESTful APIs but for web in general there's little to be found.
How can I structure the URLs of the web pages so that they are
To apply some context let's assume there's groups
that contains elements
and there are uses cases to create, view, edit and delete both.
You may have had trouble finding information about this since it's a question that touches on Information Architecture (IA) and SEO, in addition to application design. If your application or site is available on the internet (rather than an internal private network) then you have to optimize multiple, sometimes conflicting, constraints:
In general, I would suggest that you start with identifying your constraints, and consider "what makes sense to users" as a high priority one. Then try to work in other constraints from there. Since you mention separation of concerns, you have a good sense of what some of your design constraints are. Ultimately, it's up to you (and maybe your business SMEs) to determine which constraints need to be rigid, and which others can be relaxed.