routing between multiple vpn connections

I currently have a Fortigate 100C with 2 IPSEC VPN Connections:

1) to a remote site  using a Fortigate 80C

2)to our mother company using a Cisco router

I have attached the network map - See forti.jpg

I can access the sites from here and they can access my network but the sites cannot access each other.

I have added a static route on the 80C and also my colleagues added a static route on the Cisco router, but it does not work.

Any suggestions will be greatly appreciated.

Thanks in advance