I'm working with what feels like inverted hierarchy here and I need
some help in linking topics with arrays.

For the sake of illustration; I have 500 products. I run tests on each of
these products before they are approved for sale. In fact I run a group of
tests on each product. I don't run the same group-of-tests on every product,
but I do use a test-group on more than one product.

Example

Product A - gets tests 1, 3, 4, and 7
Product B - gets tests 2, 3, 4, and 9
Product c - gets tests 2, 3
Product D - gets tests 2, 3, 4, and 9
Product E - gets tests 2, 3, 4, and 9
Product F - gets tests 1, 3, 4, and 7
Product G - gets tests 1, 3, 4, and 7

I want a way for Excel to "recognize" the contents of the array "1, 3, 4, 7"
and associate it with Products A, F, and G. Similarly I want Excel to
"recognize" the array "2, 3, 4, 9" and treat that in a manner such that it is
associated with Products B, D and E.

The test-groups are easily envisioned as subordinate to the Product. But, I
want to make the test-groups one rung above the Product in terms of
hierarchy; grouping Products by test-group.

There are too many variations of test arrays and too many products to do
this manually or visually in less than a day. And as with anything tedious
and manual, there is opportunity for error by doing it that way. Can Excel
handle this task with ease? I hope.

Thanks