I am working with iOS 9.2 & Swift 2.1 & FBSDKVersion: 4.7.0.
I tried with Graph API Explorer, at that time I am getting the desired output.
The converted code is in Objective-C and I changed it to Swift.
let graphRequest : FBSDKGraphRequest = FBSDKGraphRequest(graphPath: "/me", parameters: ["fields": "hometown"], HTTPMethod: "GET")
graphRequest.startWithCompletionHandler({ (connection, result, error) -> Void in
if ((error) != nil){
print("Error: \(error)")
}
else{
print("fetched details: \(result)")
})