Does this work if the ParentColumn on the form is set to allow multiple items? If so, I can't get it to work on my site.
childColumn: "Supplier Location",
It appears to be attempting to work. It looks like the Supplier Location field refreshes, but I never get any items in the lsit, always "(None)". It seems to me that it is not finding any matching Supplier in the Supplier Locations list.
Just for clarification, here is my structure:
Suppliers - Lookup to Suppliers list - Allow multiple items
Supplier Location - Lookup to Supplier Locations list - Display Location Name column - Does not allow multiple items
Supplier - Lookup to Suppliers list
Location Name - Text field.