A Microsoft file hosting and synchronization service.
You can keep the parent folder accessible to Anyone with the link, but I would not recommend keeping confidential files in a subfolder beneath it.
The issue is that an anonymous sharing link grants access independently of the permissions you configured for individual users. This is by design and it is a product limitation for your user scenario.
I am afraid you would have to keep those folders separate as their own independent folders, don't nest the folder in the parent folder. One you can share with the link and the other you can share with the users.