Dynamic dropdowns for multiple levels

ExcelAlteryx 

See if what I've created in the "Three Levels" tab of this workbook meets your need. I know you can add rows to the basic table in the top left region, and the resulting values will all populate the corresponding dynamic drop-down lists. Mine is abstraction in the extreme, to illustrate the concept. I may take it (created in response to your question) and go apply it to my budget spreadsheet, where I took a different approach. But I'll be interested in whether this is what you are looking for.