Update field options based on previous selection

Update the options of a dropdown field based on what the user selects in the previous dropdown field.

Overview

In this example, the options in Dropdown B will be updated dynamically based on what the user selects as the value for Dropdown A. Dropdown A's options will be Positive and Negative, and Dropdown B will display positive or negative number options accordingly.

Rule Logic

This rule should run when the value of Dropdown A is changed and when the step that Dropdown B is on is loaded.

if (DropdownA.value === 'Positive') DropdownB.options = ['1', '2', '3'];
else DropdownB.options = ['-1', '-2', '-3'];