One is related to Unit. Unit is related to Empire. Empire is related to Region. Domain is a type of Region. 
Lock is part of Drawer. Lock is related to Secure. Chain can be used for Secure. 
One <--RelatedTo--> Unit <--RelatedTo--> Empire <--RelatedTo--> Region <--IsA-- Domain 
Drawer <--PartOf-- Lock <--RelatedTo--> Secure <--UsedFor-- Chain 