Dependent Drop Down lists and Data Validation; Multiple Lists

Question

Right now, I have

My goal:

Add a Data Validation List into another sheet such that when I select an item from Column B, everything from Column K appears that is linked through into Column B (examples highlighted in my screenshot above).

Right now I have a list set up in another sheet to load my Column B into this sheet's M2, then M2 to M4, then M4 to M5.

Since I couldn't figure out how to build this structure, I just created a massive list of all possibilities that each selection from ColB could have, and have M21-M25 calling to that list. Doing this would allow me to remove Row4(which calls to columns D->E from my list screenshot) from my primary sheet I assume, which I'd like to do.

I've taken a look at Microsoft Excel 2007 - Drop down list that grabs multiple columns from another sheet, but I'm not really sure that this is the advice I need.