Simple answer NO.
Complex answer, maybe but it requires a managed switch with port forwarding and those cost much more than the nas box.
Again it should be possible for someone on a different subnet to log in to the nas using FTP via the WAN but it would require that you have the necessary settings and ports opened in your modem/router that would allow connections from the internet.
If this is a work environment then you need to talk with your IT people, they may have the necessary managed switch already in place.