Restrict directory browsing for lan

hi,

My Lan port is all using a static ip / public ip address (101.22.2.33 to 101.22.2.48) <- just a sample Ip address.

1 of my lan is connected to a file server (101.22.2.35). this file server is being access by our remote offices.

  - How will restrict the directory browsing of this file server. for example, I only want our own offices to have the access to this fileserver,, all other connections should be blocked. 

thanks.