Share specific file on File Server

Hi all

Soon we are going to switch to Windows Domain and Windows File Server because the organization I'm working at is growing, and so is the need for a more professional environment.
Currently we are using Nextcloud. On Nextcloud it is possible to share a specific file with a certain person.

I'm trying to achieve the same on a Windows File Server.

I'm managing all the permissions with NTFS permissions, so every department can see only their files.
What I want to achieve is the following:
A student/intern joins the organization, by default they are not allowed to view/access any folders/files.
But it is possible that the department manager wants to give a specific student access to certain folder/file.
How do I achieve this?

I tried adding this person under the security tab and giving them read and write permissions, but they are still not able to see this folder/file. It is important to note that this specific folder/file is a sub folder/sub file under the department directory.

So to visualize:
This is what the directory looks like:

• Department 1
• ----- Sub folders/files
• Department 2
• ----- Sub folders/files
• Department 3
• ----- Sub folders/files

So a permanent employee from Department 1 is able to see alle the folders and files under his Departmentm but not from other department (this part I have).

What I want to achieve is:

• Department 1
• ----- Sub folder(s)
• ---------- sales.xlsm

What I want is that the student should be able to access the file sales.xlsm. He should be able too see the parent directories of the "sales.xlsm" file, but not other files in those directories.

Is this possible?
Thanks a lot!