I just took a look at it. I'm afraid I'm not able to figure out what to make of the various tabs within that workbook, nor how to connect what I see there with what you describe in your initial post.
It's a serious mistake to put so much energy into making a spreadsheet look great before you've gotten it to function as you want it to. As you've done it here, for example, you have set up sections that refer to variations in hard elbow parts (or some such), each much the same thing, but with some differences that lead you to create separate sections.. In general, you'd be better served with a single database of comparable parts, with column entries that take care of differentiating the specific variations that you have handled visually by separating them. Excel is wonderful with functions like XLOOKUP, INDEX and MATCH or FILTER (etc) in extracting data from a single consolidated database. Our human eye thinks it's clearer to separate the subsets, but doing so actually interferes with Excel's abilities.
Anyway, I'd be happy to try to help--you clearly have done some good learning, by the way--but you're going to have to do some more work to orient us to the way your workbook is organized, and specifically where the help is needed.