Limited support
This feature is only present in Portal 2: Community Edition. Getting Started
P2:CE includes the ability for sourcemods, mappers, and addon authors to create custom campaigns. These custom campaigns can then be published to the Steam Workshop. A campaign refers to an organized bundle of maps, which could be tightly related (such as story-based campaigns) or have no relation at all (map/competition packs).
P2:CE's campaign system is the primary form of user created playable content. For standalone maps, an auto-generated campaign addon is created. These campaigns are not visible in the interface and instead display within the "P2:CE Workshop" section as a single playlist.