Linking Multiple Servers?

I just wanted to see if anyone out there has done this.

I have a client that currently has a Mac Server running here at their office. They are going to start having offices out of state, and will want to have those users remotely have their own servers for their work out there. He would like to be able to login into the server here and see their remote servers as share points along with his local server's sharepoints here.

We are thinking of sending out to a remote office a Kerio Firewall > Mac Mini (Sierra) > and a RAID storage to store that data.

Is it possible to link the servers together, so say if he went to Finder > Go > Connect to server and connected to his example local server afp://192.168.0.x that it would show the local share points and the remote ones together in the list.

Thanks.