I have a scenario in which a ListA has two dropdown fields(dropdown1 & dropdown2) with look ups and a multiline field for description. Dropdown1 is a lookup for a listB called countries. Dropdown2 is a lookup to a field in listC called regions with a cascading effect i.e if a user selects "CountryA" dropdown1, dropdown2 is automatically filtered with the regions of the countryA . ListC has more fields like country, region, description etc.
My question how can I autopopulate the description field from ListC based on the dropdown1 & dropdown2 selection?