I don’t even know what “see the file system” means.

It just means they want to see the hierarchy that the filesystem exposes. Here's a useful diagram [0] from the Wikipedia page on hierarchial file systems [1]. There are ways to show paths and directory structure in finder, but you're fighting against the intended usage.

[0] https://upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Fi...

[1] https://en.wikipedia.org/wiki/Hierarchical_file_system