There should be possibility of customer wise item wise and vice versa item wise customer wise sales analytics can be seen we have not getting any idea from if any customer what product items he is purchasing in qty or value from report or if any customer is selected which products items purchasing trends.
Try" Item-wise Sales History" report
I did tried it was not giving item wise customer wise on both parameter. Blank result.
You will need a custom report for that.
It will me something similar to item wise sales register but with customer and item filter.
Have you tried item wise sales register? I hope its different than history.