Not able to connect remote SSL VPN users

Hi,

I have a Fortigate firewall in head office where we have configured ssl vpn. From the other branch offices where we also have fortigate firewall, we are not able to take rdp of the remote WFH users who are connecting through ssl vpn client. Kindly help how to configure the branch office firewalls from which we need to take rdp of ssl vpn client users.