471456 Sobi2 Filter

I am using Sobi2 for a business directory I need visitors of my webpage to pre-select a state (eg CA) and/or a City (eg Los Angeles). Based on that selection I want all categories and sub categories to only contain entries based on that selection. The module should work as a drop down menu to select the state and then the town. Its kind of like what you have using the [login to view URL] but I would want a drop down menu to preselect. I have attached a pdf file where I drew boxes for the state and city select drop down boxes. Again, once a state is selected only entries within that state should show within the below categories and sub categories. Thanks a lot. Regards, Andreas