Can anyone help me with a binding on a multiple dataset query?

I have created a multiple dataset query containing 2 datasets. Now I try to add a binding to switch between 2 dimensions in the query; totalprice and quantity. 

I have added the same binding to different tables and graphs and it works fine. I'm struggling with the binding on the multiple dataset query. Does someone knows how to add it to the JSON? 

The binding which I have used in the other queries is:

"{{column(Waarde_static_1.selection, [\"value\"]).asObject()}}"

I have added printscreens of the JSON of the multiple dataset query.

Thank you in advance!! Marjon

#Analytics