You can set up an RV0xx, WRVS4xxx, RVS4xxx or other IPsec capable Small Business VPN Routers for Gateway to Gateway VPN Tunnels. You can define the subnest or IP address ranges you want shared across the tunnel. This is pretty intuitive in the Web GUIs for these devices.
But did you know you can also force ALL traffic from one Branch router to a Central Office router using the same Gateway to Gateway IPSec Tunnel, basically administering a 0.0.0.0 default route to send all traffic out of the branch to the other (Central) Router?
This cheat sheet shows you how.