Setting Advanced Permissions to ON allows you greater control of which users and classes get sent to a vendor. This allows you to export a class without also exporting the entire associated course and org.
Note: By default, unenrolled users will be left out of advanced permission controls. This means that even if a users exists in a selected org, they will not export unless they have one or more enrollments.
The number of orgs and courses you select from basic permissions will determine the number of classes and users selected. These classes and users are dependent on your org and course selections.
By manually adding classes to the selection, you also increase the number of users selected.
You also have the option of removing users who you do not want to be included in the export. Classes and Users who were added as a result of a Course or Org selection, (i.e. by dependency) will have a green check mark box. Classes and Users who were manually added will have a blue check mark box.