Power Bi: Top N visual level filter as Measure

Question

Need a measure that will provide the same output as TopN visual level filter (than I can parameterize it).

The solution for simple cases provided HERE

But it doesn't work for more complicated cases...

EXAMPLE:

Don't work if you add any dimension that has Many to One Product Name relationship (Order Number for example).

Desired output: both tables (top and bottom) should be equal:

Example from screen available here HERE

NB! From usability perspective it's preferable to return Sales Rank in measure.

Answer 1

A bit reworked solution from David Bacci:

1. If you need just TopN Sales:

TopnSalesAmount = 
VAR param = [TopN Value]
VAR topNTable =
    CALCULATETABLE (
        TOPN ( param, 'Product', [Sales Amount], ASC ),        
        ALLSELECTED ( 'Product'[Product Name] ),
        FILTER ( ALLSELECTED ( Sales ), [Sales Amount] <> BLANK () )
    )
RETURN
    IF (
        NOT ( ISEMPTY ( Sales ) ),
        IF (
            SELECTEDVALUE ( 'Product'[Product Name] )
                IN SELECTCOLUMNS ( topNTable, "a", 'Product'[Product Name] ),
            [Sales Amount]
        )
    )

2. If you need Rank for TopN Sales:

rnkTopnSalesAmount = 
IF (
  //ISINSCOPE ( 'Product Names'[Product Name]), -- depends, which one is used in visual
    ISINSCOPE ( 'Product'[Product Name] ) 
    && NOT ( ISEMPTY ( Sales ) ), 

    VAR ProductsToRank = [TopN Value]
    VAR topNTable =
        CALCULATETABLE (
            TOPN (
                ProductsToRank,
                ADDCOLUMNS ( VALUES ( 'Product'[Product Name] ), "@Amt", [Sales Amount] ),
                [Sales Amount], ASC
            ),
            FILTER ( ALLSELECTED ( Sales ), [Sales Amount] <> BLANK () )
        )
    RETURN
        IF (
            SELECTEDVALUE ( 'Product'[Product Name] )
                IN SELECTCOLUMNS ( topNTable, "a", 'Product'[Product Name] ),
            RANKX ( topNTable, [@Amt], [Sales Amount], ASC )
        )
)

Answer 2

Here you go.

BottomN = 

VAR param = [TopN Value]
VAR topNTable =  CALCULATETABLE( TOPN(param,'Product', [Sales Amount], ASC), ALLSELECTED('Product'[Category],'Product'[Product Name]), FILTER(allselected(Sales), [Sales Amount] <> BLANK()))
RETURN 
IF(NOT(ISEMPTY(Sales)),IF( SELECTEDVALUE('Product'[Product Name]) IN SELECTCOLUMNS( topNTable,"a", 'Product'[Product Name]) ,[Sales Amount]))