Relate Options across different fields

I recently spent some time reworking how our platform handles relationships between different list fields.

Many of the larger events on our platform need to create tiered options lists.

For example:
What region of the festival do you need your tent?
[list of festival region]

What specific area?
[more specific area] - filtered down based on previous field

The challenge was to be able to create & manage these option relationships in an easy & intuitive way.