Subnes Communication

I write to ask about granting permissions for a Subnet(10.5.2.X) to access Folders on another Subnet(10.5.1.X).

I need 10.5.2.X to have access to a Group Policy location on a Windows Server 2008 Domain Controller(For both 10.5.2.X and 10.5.1.X). But with the current configurations 10.5.2.X cannot see machines on 10.5.1.X

I have ensured the Firewall/Router is not blocking access.

Any help will be appreciated