Variable Dependent Drop Downs

I have added a bunch of named ranges in your WB.

To use dependant dropdowns, you need to have range names for all your data ranges, and then the DD references the 2nd and subsequent levels using an INDIRECT() reference to level 1 (for level 2) and to level 3 (for level 2)

You did not really have a level 3 set up, so I kinda dummied 1 up in column J to show you how to apply it. To see how it works, look at "Source" in teh DV window. I had to use the SUBSTITUTE() function to swap a space with a _ because DV named ranges doesnt like to work with spaces