I have no idea where to go from here.

I'm trying to make a dynamic list of items and their locations.

I have 7 bays labeled A-G which are each divided into 2 to 4 different sections labeled A1, A2, B1, B2, etc. In each section I have between 1 and 18 items which are each numbered. I have them in sheets by bay now, but I need an additional listing that has all the item numbers in numerical order, and lists which section(s) each can be found in.

Where do I go from here?