How to share .bash_profile between different users in the same group? I have searched by google but cannot find a right solution.The scenario is like this: in my mac, there are two users, lets say user1, user2. these two users are in the same group, which is staff actually.

Now in user2, there is a .bash_profile for user2's terminal, can i share this profile with the user1? I know i can copy one from user2 to user1. but if i copy one, when there is something changed in user2, i have to copy it again. I wonder whether there is a way to share it with user1?
i work it out by using command ln -s /Users/user2/.bash_profile /Users/user1/.bash_profile. 
But by only this command, i can only change the .bash_profile in user2. in user1, you can only use the file in the read-only mode. Then i check the .bash_profile privilege in user2. its rw-r--r--. So i do chmod 664 /Users/user2/.bash_profile. Finally i can share the .bash_profile in different users.