The campaign audience is a group of users who are allowed to view and submit ideas within a campaign.
Open the campaign you want to define the audience in. Click "Edit Campaign" from the menu.
Go to "Step 7 of 8 - Audience".
"Invite all active system users" allows all users within the system to access the campaign. "Manually define Audience for the campaign" will allow you to select specific users for the audience.
Select Profile Criteria allows you to select groups of users based off of criteria within their profile fields.
Add Profile Criteria as a list allows you to add a list of profile field values that will be present in all audience members. Up to 200 users can be added at once.
Invited Specific Users allows you to manually select users to add to the campaign audience. This section also allows you to invite external users to the campaign.
For more information on how to customize the Campaign Audience, please visit: