Bitly paid customers have the ability to redirect any and all of their custom bitlinks (Bitlinks that have both a branded short domain and custom keywords) to different target URLs.
If you do not see this functionality within your Bitly account it means you don’t have the ability to redirect a link. If you are interested in upgrading to Bitly Enterprise please reach out here.
You can redirect a Bitlink by selecting the orange "Redirect" button below the bitlink in the "Bitlink Management" section.
You will also be able to see the redirect history of that link. This will all be in the “Custom Bitlinks” section.