In the past a property could only be assigned to one category which could be used in filtering properties. Of course filtering by # of bedrooms, price, amenities, etc was possible.. but search by location was limited to one parent category. Thus if you have properties in Paris, your search location would be limited to Paris. Now however subcategories can be assigned to parent categories allowing properties to be assigned to any of Paris’s arrondissements or areas.
Read the full blog post on this great new feature.