When using Network Folders with NTFS permissions, it is possible to automatically hide folders that users don't have access by enabling Access Based Enumeration (ABE) settings.
To enable ABE, go to Admin Portal->Settings->Storage->Network Storage tab and enable the "Enable Access Based Enumeration for NTFS" checkbox. This will enable ABE globally.
To disable or enable ABE only for specific network folders you can open up the specific Network Folder Properties dialog. Admin Portal->Network Folders, click on "Edit" for a network folder.
Select "Global Policy" to use the global setting, or use the "NO" or "YES" options to disable or enable ABE only for this network share.