Aperture's smart album filtering logic offers only the most basic logical choice: all the conditions set in the dialog or any of the conditions set in the dialog. This means that while there are many different criteria provided, it not apparently possible to combine them in complex ways.

However, due to the fact that there are actually two levels of filtering provided by the thumbnail and grid views, impossible filters can be constructed. For instance, I can find images taken on Wednesday OR Thursday OR Friday AND at between 100 and 130mm focal length. I can find images with the keyword Duck OR Swan OR Goose AND the keyword Lake AND rated two stars and above. And if I want, I can make these type of smart filters specific to a single project or to a collection of projects in a blue folder.

Here is how to combine logic using the two available levels. I'll use the requirement that I need to view all RAW images taken in 2007. To find all RAW images I have to create a filter that ORs together all the different kinds of RAW there can be, since there is no setting for "is RAW".

First I select the library and create a new smart album and call it RAW-2007:

I select the Library before I create the smart album because I want this to work on all my images. The dialog reflects this in its title.

Then I set the match to be ANY and filter to Filename ends with .CR2. I add some more conditions for the file name ending that deal with all the RAW formats I am going encounter:

I could check the Ignore stack groupings box at the bottom if I wanted to look inside stacks. This first filter finds all the RAW images in my library.

I close the dialog and with the smart album still selected I click on the filter icon on the browser, top right.

To set up the second level of filtering I filter on the EXIF capture year and match it to 2007:

I could add more conditions at this point, such as ratings or camera model, if I wished.

To make more filters similar to this one, say for different years, I duplicate the smart album, rename it, and then change the year number in the filter:

This second level of filtering works because each album, project, and smart album remembers its current filter setting. I have to be careful not to change it once I have the thumbnails displayed or else it will not work as expected when I reinvoke it. One way to reduce this risk is to select all the RAW-2007 images and create a new regular album from them (or just use the New Album With Current Images button) Since no more images will be added in 2007, the contents of that static album should never change.