Not quite sure whether you would like a hard code for cross items or dynamically, and also how to determine which category is the main product. but below is some idea of how to populate the data as cross join.
use inner join your data to itself with key 1=1 as shown below
And the view should be something like this
Hope this helps
Can you post an Excel example of what your end result should look like?
Hi ZZ and Albert,
Actually, this is almost exactly what I would like to achieve. I did write it down a bit messy, I am sorry.
What I would like to achieve: that the Category column will be transferred to rows, see attached a example of what I would like to achieve.
testcrosssell.xlsx 9.9 KB