At the top of the screen Manage Campaigns there is a search bar Find Entry that allows you to look for a specific campaign, or narrow the searches from the full list of campaigns if you are looking for a common feature of certain campaigns.

Enter the term that you want to filter the search results by and click the Find button to the right of the search field.

Test

Once Find has been clicked, all campaigns with the combination "QA",  in this example, will be presented.

Find Campaign

Note: The Find function only searches based on the Campaign name field.