By default all your users/affiliates can have access to multiple campaigns. To create a special campaign for an affiliate you can follow the simple steps underneath.
1- From your Admin control panel go to Campaigns and click on Adding new campaign.
Step 2: Here Fill out the necessary information which will be displayed to your affiliates and Click on the link says "View Advance Settings"
Step 3: Now unchecked the field says "Make Available To All Users" and continue.
Finish the setup for your special campaign.
Step 5: Please go back to your Dashboard and Click Users and Click at pencil button to edit user.
Step 6: Click to assign special campaign to this specific user.
And Update to finish the setup.