It's entirely based off usergroups and view access levels. Select the moderator view access level within CB > Configuration > Moderation. Anyone who has the usergroups of that view access level will be a CB Moderator. To toggle emails on for a moderator you need to edit them within CB > User Management and set them to receive moderator notifications.
Please read your CB 2.0 Primer Book as it describes this and more. You may also want to go through our extensive list of CB 2.0 videos covering basically all of CB.
www.youtube.com/playlist?list=PLp0puRITgC7PuyzPsMUECDI46VE7IFSAX