When a group was denied access to a shared team folder's sub-folders, but a single user from the group was given access, the other users in the group could view sub-folder names. This has been fixed.
In version 22.214.171.12494, this has been fixed so that users who were not given access to the sub-folders cannot see the sub-folder names.
If you are using the FileCloud on-premise installation, please update it to the latest version, which is 126.96.36.19994 or greater.
If you are using FileCloud online, your site has already been updated to the latest version.