What you show above will throw an error because you have the comma at the end of this line:
listName is only useful in this function if you're calling it from outside the list context, e.g., not in /List/SomeList where the forms usually live.
M.
childColumn: "Product",
The last option shouldn't have a trailing comma. listName is only useful in this function if you're calling it from outside the list context, e.g., not in /List/SomeList where the forms usually live.
M.