How to create multiple level dependent dropdown list?

Demo Form: 3-level Dependent Dropdown, Country > State / Province > City

To setup a multi-level dependent dropdown is super easy, with magic hashtag #depend marking options are shown (depended) based on a parent option value, you can easily create a unlimited level cascading drop-down list in a html web form.

Here are the steps:

1. Create a normal Dropdown field
2. Create a second Dropdown field, check the option "Is a dependent field?", and select the parent Dropdown field that depends on.
   
3. Use #depend hashtag to define options that depend on the value of a parent option
   

The big picture on how to define options for a dependent dropdown: Country > State / Province > City

Demo Form: cascading drop-down list