There is no option the define a second user for USB storage file sharing (or ftp). You dont have an option to share ONLY some folder sharing with your guests or childern and no option to hide private...

@Kicel I see same problem there is suffix after folder name, for me it is : \\alihome\home_disk(sda1) and this is very stupid design to me. But I aware someting you can use it even without that...