Hi Michael,
In a nutshell, B One can serve as both OpenVPN Server and Client.
If you want to set up a Open VPN server,
Go WebAdmin >> Advanced Tab >> Remote User Access Settings
The B One user manual page OpenVPN section describes how you connect to a OpenVPN server as a client. You will need to obtain the profile from the service provider to form this site-to-site tunnel.
If you want to utilize outbound policy with OpenVPN (Better control of internet traffic), you can buy the OpenVPN Activation Licence as well.
Reference: