If all users have the Shared Contacts feature, they will automatically have access to all users in the Enterprise Contacts list. Follow these instructions to manually share your Enterprise Contacts:
1.) Go to the Preferences menu and select Share Enterprise Contacts.
2.) Click on Edit Sharing for All Contacts while viewing the Sharing Settings.
3.) Add or remove users and/or groups that should have sharing abilities and assign their access to Read-Only, Modify, or Full Access.
4.) Click Update to apply the changes.