Hide files or subfolders in shared parent folders

Nextcloud version 17.0.2

Dear Nextcloud community,

Is there a way to hide files and/or folders for certain users or user groups?
We’d ideally do this based on tags such as “confidential”.

With “File Access Control” it is only possible to block access to those tagged files/folders, but the files/folders still show up. We’d like to be able to hide them.

The files marked as confidential must also not be synchronized with the desktop app or displayed in the file structure when accessing WebDav!

The following is an example of an use case:
Customers - shared folder with all sales agents
Customers/customer_1 - shared folder with sales agent handling this [1] account and supervisor.
That folder should be hidden from other sales agents.
Customers/customer_2 - shared folder with sales agent handling this [2] account and supervisor. That folder should be hidden from other sales agents.

So all users will see
Shared/Customers/
But each agent will see there only folders for his clients and supervisor will see them all (in same structure)
One sales agent will see
Shared/Customers/customer_1
Another will see
Shared/Customers/customer_2

And supervisor will see
Shared/Customers/customer_1
Shared/Customers/customer_2

Are there any ideas to realize that with nextcloud?

Many thanks for your feedback!