I am looking for a way to have two different dimensions or layers of tags/ categories. For example, one dimension could be a drop-down with different cities, like New York, Berlin and Sydney. You could select just one or all three. And then there is another dimension with different cultural things to do, like cinema, bar, restaurant and club. So if you click on Berlin it shows you all of the second dimension (cinema, bar, restaurant...), but then you also have the possibility to select "bar" and it only shows you the bars in berlin. That should also work the other way around (select "bar" and it shows you all the bars in Berlin, New York and Sydney and then refine the search by just clicking Berlin...). I don't want to nest several categories but rather have just two rows of categories which work separately and can browse through the other.
I hope my problem is understandable :)
I am really looking forward to your answers.
The blog I need help with is blaqkey.wordpress.com.