How to reference column in table variable (after TOPN and CALCULATETABLE)?

[EmielvdR]

I'm trying to select a single value (TOP 1) of a table variable which has multiple columns which where used for filtering and sorting.

I made an example in DAX.do (https://dax.do/ha0qItKqNlnWHP/) to illustrate the problem (simplified without sorting mechanism):

DEFINE

var aaa = 
  TOPN (
    1,
    ADDCOLUMNS (
      VALUES ( 'Product'[Product Name] ),
      "myTotal", [Sales Amount]
      ),
    [myTotal],
    DESC
   )

EVALUATE
   aaa

"aaa" return two colums in 1 row. I want to access only the "Product Name" column.  I need the intermediate variable "aaa".

It's not possible to select it by "aaa[Product Name]".  I found: https://community.powerbi.com/t5/Desktop/DAX-Is-it-possible-to-refer-to-columns-of-a-table-variable/... but I'm unable to translate this to my situation.

[DataInsights · Accepted solution]

@EmielvdR,

You can reference the column in the original table since the lineage of the virtual table is maintained. In the measure I defined below, notice the second argument of MAXX: it's the underlying table/column. I had to wrap the result in curly braces since this tool returns only tables (in your model, you won't have to do this).

DEFINE
    VAR aaa =
        TOPN (
            1,
            ADDCOLUMNS ( VALUES ( 'Product'[Product Name] ), "myTotal", [Sales Amount] ),
            [myTotal], DESC
        )
    MEASURE 'Product'[Top Product Name] =
        MAXX ( aaa, 'Product'[Product Name] )

EVALUATE
{ [Top Product Name] }

[EmielvdR]

Thank you! Worked perfectly!