How can I allow a single member of group as sudoer

I am looking for a solution to a use case where a group is granted sudoer privileges. However, only one specific user or member within that group should have sudoer permission privileges, while the remaining members of the group should not have permission to access sudoer privileges. In summary: A group has been granted sudoer privileges. Only one member of the group should have sudoer privileges. The rest of the group's members should not have sudoer privileges.