Drillthrough not showing selected elements

Question

I've selected several elements that I want to see in my drillthrough, but not all of them are displaying in the query itself. Why are they missing?

 

Answer 

Only attributes or metrics that are selected to include in your query itself will show up in drillthroughs. This means if any of the attributes selected in the drillthrough are not already included in your query (as a row, column or filter), they cannot be shown in the drillthrough results.

 Contributed by community member Darren Taylor.
For the original conversation, see Drillthrough Not Showing Columns Selected.