Core is related to Planet. Planet is related to Sphere. Sphere is a synonym of Area. 
Placement is related to Middle. Middle is related to Spot. Spot is related to Bed. 
Core <--RelatedTo--> Planet <--RelatedTo--> Sphere <--Synonym--> Area 
Placement <--RelatedTo--> Middle <--RelatedTo--> Spot <--RelatedTo--> Bed 