Pig is related to Farm. Farm is related to Setting. Scenario is a type of Setting. 
Bubble is related to Level. Level is a synonym of Plane. Plane is a type of Machine. 
Pig <--RelatedTo--> Farm <--RelatedTo--> Setting <--IsA-- Scenario 
Bubble <--RelatedTo--> Level <--Synonym--> Plane --IsA--> Machine 