When attaching an output file to a Chatter Group as a Community User, you must specify the Chatter Community (via its Salesforce ID) to which the file will be visible.
Category: Chatter Integration Parameter
Compatible with: Composer 8
Parameter Name: ChatterCommunityId
Parameter Value: [ChatterCommunityId]
Parameter Requirements: None
Parameter Description: ChatterCommunityID specifies a Chatter Community ID. When attaching an output file to a Chatter Group as a Community User, you must specify the Chatter Community (via its Salesforce ID) to which the file will be visible. Note:Chatter Community IDs begin with 0DB