Unfortunately at this time you can only display 1 campaign on a single URL.
If by accident you do have 2 campaigns set to display on the same url, then your notifications will not function properly.
For example, let's say you create a campaign for users that "recently purchased an item" and another for users that "subscribed to the newsletter". You cannot have both of these 2 unique campaigns displaying on the same URL. Instead, we'll need to set these campaigns to display on two separate URLs.