I need a Joomla extension that can allow for a visitor to select a category for e.g. City, then it must open another drop down of the cities, and then it must display a list of all the selections available in the city. here is an example: http://www.placidway.com/
on the left there is a search section titled: "Find Medical Procedures". One search takes you to another search until you narrow down the selection. If nothing is available, any suggestions as to how to go about something like this would be greatly appreciated.
Thanks in advance