Changing order of conditional drop down selection

We are trying to build out an inventory database that shows products available and the stores you can buy them at.  I understand how to set up Conditional drop downs (Manufacturer limits Make limits Model) but what if you want to be able to search by more than one starting point.  So you can see that XXX Company makes 3 types of TVs (36", 55" and 70").  The 36" inch TV can be purchased from Vendor A or Vendor B, the 55" TV is available from Vendor C and Vendor A, and the 70" TV is available from Vendor B and Vendor C.  But could you start by selecting Vendor A and seeing that they sell TV and stereo equipment and the TVs they sell are available in 36" or 55".  Think using the Filter function on Excel and selecting any column on your spreadsheet and seeing the rows drop down from there.