Power BI - DAX language RANKX function for TOP 5 only

snph1777 

I don't know of any way to do it with only measures.  The reason being, you need somwhere that the value of 'Other' exists along with the list of products.  That is a simple calculated table to create with code like this:

Product List = 
UNION ( 
    DISTINCT ( 'Product'[Product Name] ),
    ROW("Product Name", "Other")
)

You join this new table into your existing product table and pull the product name from the new table for your report.

Then you can make a TopN measure that will show the top 5 and group the rest.

TopN = 
VAR Top_N = 
    CALCULATETABLE ( 'Product List', TOPN ( 5, ALLSELECTED ( 'Product List' ), [Sales Amount] ) )
RETURN
    IF ( 
        NOT ISFILTERED ( 'Product List'[Product Name] ), CALCULATE ( [Sales Amount], ALLSELECTED ( 'Product List' ) ),
        IF ( SELECTEDVALUE ( 'Product List'[Product Name] ) = "Other",
            CALCULATE ( [Sales Amount], EXCEPT ( ALLSELECTED ( 'Product List' ), Top_N ) ),
            CALCULATE ( [Sales Amount], INTERSECT ( 'Product List', Top_N ) )
        )
    )

In order to sort 'Other to the bottom of the list you would need a measure liks this and add it into your visual then set the column width narrow enough to hide it.  It is just there to sort.

TopN Sort = 
IF ( SELECTEDVALUE ( 'Product List'[Product Name] ) = "Other", 0, [TopN] )