Glad you liked the article! :D
About your problem.
I have no idea how your resources are linked together, but from what you are saying you're fighting a bit with redundancy.
One possible solution could be the creation of a root resource for files that handles all CRUD actions and then add nested resources for read actions only that just respond with redirects to the corresponding files resource.
That way you could read /comments/1235/files when needed and only had to implement something like /files?comment=1235 that is the target of the redirect.
You're right, it's hard to say without the whole context :) But I won't describe the whole thing here as I don't think it's the right place to discuss complicated problems :D
Anyways, your article gave me some insight on the problem and some ideas on different approaches with nested resources :) Also thanks for the suggestion in your comment as I didn't think about this kind of solution!
You are welcome :)
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