To build on Rafeeq's Suggestion, you could also create a "Management Server List" for each group. I.E. Create a new policy for each group (subnet/location).
For example, by assigning all the machines in NEW YORK subnet to a group and than assigning Management Server List Policy to that group.
In the policy you could specify the "server name" for that particular subnet.
Thus all machines in that group, would apply it's policy to look for a server named X as is indicated in the policy, definied to that group.
By doing this, you would most likely need to ensure that "inherit policies from parent" is unchecked. You want to make sure that the policy you assign is being assigned and implemented to the proper place.
You would than need to ensure to apply the other policies to all the groups and make sure when modifying, you are modifying your other policies- other than the one stipulated above, as shared.
Either way should work.