Tag filters for grid layout?

Question

I have an irregular "metro-style" grid of items of various types: Blog posts, press releases, reports etc. To the left, the user should be able to filter the grid by Topic and Content type.

The topic list is however growing (it will reach a max of 20 items), each belonging to one of three overarching themes). As the mockup shows, I would somehow like to show the theme headings even though only topics are selectable.

What would be a better way of allowing the user to filter by Topic and Content type, still showing the theme headings somehow?

Replacing the current with 2 dropdowns? Dropdown for Topics and radio buttons for Content types? Other?

Answer 1

I think of something more metro-style look and feel. Minimalistic and flat buttons Topics and Content for filtering options, which expand to large options area. So you don't bother of Theme and Topics growth. Mixing topics list and metro-style grids, as on your sketch, is a bit inconsistent.

Answer 2

I would say that the current taxonomy suggests that the Content types are subsets of the topics, Eg. a scenario could be "show only Blog posts regarding Topic C". However, the current layout doesn't really convey this since they are grouped in the same filtering area. Instead I would suggest that you move the Content types filtering control out from the left panel and instead place it on the top of the content as a horizontal control (such as a tab bar/segmented control).

This way you separate the different filtering features to better convey their effect on the displayed content.