Multiple search terms from dropdowns?

I have a custom field group of ‘producers’, which refers to food producers. This group has categories like ‘meat-and-poultry’, ‘eggs-and-dairy’, etc. One of the custom fields in the group is ‘county’. I would like to create a search option that allows users to select a category and a county from two separate dropdown menus. So, for example, they will see, “Show me all ______ producers in ______ County.” In place of each blank would be a dropdown showing possible choices. They would select one from each and click Search. Can I do this in Relevanssi, and if so can you please point me in the right direction to research how to do it?