Webform auto-fill-component on-select

Trying to figure out how to view a parent component value that was selected (on-select trigger), so I can pass it to another component on the same webform. The child component would use the passed-in parent value, to determine what values to display itself. If I can figure out how to pass the component value, I can extend something like webform_term_options, that uses a pre-built list, to use a dynamic one instead (I believe).

Example:
If I choose a Product from a select list, that has a condition to show another select list on select X value. How can I pass the product/value selected to the other select list? Based on the value of the first list, a version/value can be determined programatically in the second list.