A business user is any person from your business with access to either the Field View web application or the Field View device app. A business user can be assigned to multiple projects.
You can add a user to your business in the Field View web application. Enter the user's profile information and create a user name and password for that user. Once created, make sure to inform the user of his or her user name and password. Once you have added a user to your business, you can assign that user to projects.
Alternately, you can invite a business user to create his or her own user profile, including user name and password. However, invitations expire after a set date, usually 30 days, if the user doesn't act on it.