Lock is related to Drawer. you are likely to find Shirt in/at/on Drawer. you are likely to find Shirt in/at/on Closet. Closet is related to Safe. 
you are likely to find Wheelchair in/at/on Hospital. 
Lock <--RelatedTo--> Drawer <--AtLocation-- Shirt --AtLocation--> Closet <--RelatedTo--> Safe 
Hospital <--AtLocation-- Wheelchair 