There is nothing special about this "loop". The relationships and tables that you need are identified by the business rules/facts that represent your business. Part of the task of database design is to identify all the business facts, identify the subject areas, identify unique attributes and to establish relationships among the entities using the rules of Normalization.
I have suggested previously that you go back and read posts #5 and #7, and am doing so again -- read posts 5 and 7
Good luck.