Routing from 1 pfSense/OpenVPN site to another over established site-2-site connection

[peterLinux]

I would like to know what 'routes' (where) are needed to allow somebody who connects to the (existing) road warrior openVPN on site 1 to open up a Rdesktop somewhere on 192.18.247.0/24 on site 2...

The blue dotted line is the unknown for me.

[viragomann]

The road warrior VPN clients need routes to the subnets at site 2. At site 2 you need a route tor the road warrior tunnel subnet.
That is all done in the OpenVPN settings.

So at site 1 in the access server settings add the subnets of site 2 to the "Local networks". That pushes the routes to the client.

At site 2 in the site-to-site settings add the road warrior tunnel subnet to the "Remote Networks". So OpenVPN sets a route for it pointing to the remote endpoint when the connection is established.

Also ensure that your firewall rules allow the intended access.