Cascading select list script with parent from CRM-for-JIRA

[Himanshu Nanda]

I have these Customer attributes stored in "CRM for JIRA" Plugin - "customer name" and "products".
When creating a ticket/issue, the product selection is thus dependent on customer selection (cascaded via CRM).

Now I want to add another custom field called "Component" which would depend on product. And this third level cascading is not doable via CRM.

Trying to use script runner here - https://library.adaptavist.com/entity/dynamic-select

This script works with standard single select lists. But if the parent is a CRM type select list (CRM Custom Directory), it doesn't seem to work. Please help?

Product field type = CRM Custom Directory (behaves like a drop down)
Component field type = Single Select List

(Open to alternative suggestions as well to achieve this 3 level cascading)