how to vew other island on facebook game ?,hw to access other island on facebook game unity3d?

im developing facebook game on unity consist of island i need to other players have access to view other island in the game
any help,im developing a facebook game consist of islands i need every one that is payuing this game view other island

This is a very broad question. And there can be many was to achieve this. But here is a simple explanation to help you point in better direction.

First you will need to make a scene in such a way that can read different properties of player island from data stream and display it correctly. (I would have used xml as a medium of data stream for my scene).

Secondly you will have to find a way of transferring that data to your server and then to different players. (saving players xmls on Google firebase ?).

Thirdly its simply matter of loading different data files using the scene created in first step.