An arrangement of code values from multiple code lists below, above, or at the same level as other code values. The code values that you can arrange depend on the hierarchy model.

For example, you might have a hierarchy model with the Region code list defined as the top level node and a relationship from the Region code list to the Country code list. Then in the hierarchy, you can create a hierarchy relationship from the North America code value to the United States code value. You might also create a hierarchy relationship from the North America code value to the Canada code value.