since very long time i was finding solution for this approach and through googling i found following details which will be really helpful to setup cascading dropdown for sharepoint list in just few mnts !!
1) download following add on from codeplex from following link
2) setup sharpeoint list as follow
lets say there is countries list as follow
then create a city list as follow that will be filter by selected country
3) create another list that contains cascading dropdown column as follow
lets say its name as "test"
here , Country column will be parent column and city column will be child column
so create first parent column for country by setting type as "parent control" as follow.
and then create a city column as child control as follow by assigning type as "Child Control"
now test it as follow
Select Germany and get a list of German cities:
Thanks & Regards,
Dipti Chhatrapati
Enjoy Sharepoint Programming !!!