Feature of Global/Shared communities would allow you to share any f your community with other sub-acocunts in your account. By making the community global you provide access of that community to the account you share with, making it easier for you to work with your team.
To set up a Global/Shared Community:
Go to: Communities >> More >> Permissions
Click on the more option next to the community you wish to share.
Click on Permission
Check the check box next to the user you wish to share the community with and click on Save Changes
This feature is available with the following license :