Set Campaign Type's that you want to be able to chose from with the "Add to Campaign" button.
Using the "Add to Campaign" button, the list of Campaigns can be hundreds... If there were a setting that allowed you to chose which types of Campaigns you want to see in your Campaign list that would narrow down the list. I have a Campaign Type called "Location". The "Campaign Type" field is a Salesforce pick list that is part of the Campaign Object.