Thanks Mahamed for your input.
It is not completely what I am looking for.
I want to select Article 1 and than see all Customers that purchased Article 1 and more important I would like to see which other Article's those customers purchased
For the example I see in my overview that Customer B purchased Article 1. So I select Article 1
And then in another overview I want to see :
Customer A purchased Article 1 and Article 2
Customer C purchased Article 1 and Article 2 and Article 3
Customer D purchased Article 1 and Article 3 and Article 4
Based on above overview I know that when a Customer Purchase Article 1 they might be interested also purchasing Article 2 and 3.
This information we can use for upselling purposes.
Hopefully this explains it a bit better.