Registered Servers without the ability to connect to Multiple Servers at once
There is no way to avoid that once you share CMS.
Just be aware that it only stores the list of instances of SQL Servers available, but not necessarily everybody has access to connect in every single instance.

Because the connections that are maintained by a central management server execute in the context of the user, by using Windows Authentication, the effective permissions on the registered servers might vary. For example, the user might be a member of the sysadmin fixed server role on the instance of SQL Server A, but have limited permissions on the instance of SQL Server B.