Thinking About Value Lists, part 1
Thinking About Value Lists, part 2
And you might take a look at "hardwired conditional value lists" as found in "Adventures In FileMaking #1". This is a free file that you can download from my FaceBook page. "Hardwired" conditional value lists make up 2 of 8 different variations of a conditional value list that you can find in this one exploration file. Each example value list comes with detailed documentation on how to set it up and how it works.
Thank you for the tips.
This is exactly what I wanted and it remains simple to use.