You may have have seen the first links in this list already, but check out the very last one as it is a thread that discusses what you are looking for here.
Forum Tutorial: Custom Value List?
Knowledgebase article: http://help.filemaker.com/app/answers/detail/a_id/5833/kw/conditional%20value%20list
Hierarchical Conditional Value lists: Conditional Value List Question
Feel free to post follow up quesitons here if those links aren't enough to get your value lists working correctly.
Oh wow, this is exactly what I was looking for. I'll let you know if it helps. Thanks Phil (:
Worked on it for a bit with my supervisor, and found that that solution isn't entirely accurate. The value lists all should be set up as you indicated, but for future posterity, this is the one possible final relationship that should filter out all previous records simultaneously for each subsequent record. For my purposes though, it will not work any other way (:
Thank you for your help Phil.
It's basically the same solution. The difference is that the solution described in the thread is built on the assumption that each succeeding value selected from a value list uniquely identifies a set of values for the next related table of values. Thus, it doesn't need any relationships based on more than one pair of fields. This is not the case in your project so you needed to modify the details used to set up your relationships.