Indicate which boss we need to complete AP

I still need the elusive 4 achievement but I have NO CLUE which ones I still need. I would like to have an indication of which bosses we need to complete an achievement that calls for multiple bosses to complete. I finally finished all of the arena AP's last night when I got glob with spiders. I didn't know which one I needed so did a bunch of runs until I finally got the one I needed. While that works okay, a quick way to know which maps to farm would be nice.