From the above IS doc structure what i have understood is orders is the doc list and for each orderNo again u ll be having the orderLines as one more doc list, if this is correct,
U can create a groupOfOptions as a contentProvider, if u bind this to the dropDown you ll be getting the orders in that.
use a raiseOnChange control along with AsnyHiddenCommand button for the orders dropdown.
in the action, retrive the orderLines values from the resultprovider for the item that user has selected from the orders dropdown and assign those values to a string list. Bind the string list to the orderLines dropdown.
Hope this will be helpful,
In the above scenario every countryName is having some of the qualificationNames associated with that.doc (46 KB)