I added a drill-down dimension with 3 levels and used in my scatterplot. As I tried it today, that seems to work.
Although I would like to do something more advanced: the scatterplot shows 2 measures (cost and quantity) and 1 drill-down dimension (CustomerFamily --> CustomerName --> Product). I would like to plot a dot for every customerFamily for every month.
I did this by combining CustomerFamily and MonthYear, and this works, but then drill-down functionalty doesn't work anymore.