Is there a way to create cascading dropdown without using list?

Question

I want to know is there a way to create a cascading dropdown menu in sharepoint without using a list.

Answer 1

You can bind your dropdown to any other data source (XML file, database, table, embedded default values), through receive data connection. And if you have done dropdowns you should have seen this option after clicking Get choices from external data source > Add > Next

There is no difference in procedure between sharepoint lists and other data sources ...

Answer 2

You can supply the drop down values as part of the drop down properties and then use rules to populate the related drop downs. I gather it will be a fairly comprehensive rule set as you will have to check on each item select and populate the corresponding drop down values.