Creating "Others" category for a chart

Hi Lucas_Radebe 

if you want to be able to use the rank measure in a legend, you must materialize the result using a table that contains the rank numbers. 

Top N Sales with Other = 
VAR SummarizedSales =
    SUMMARIZECOLUMNS (
        'Product'[Model],
        "@rank", [Product Model Rank By Sales],
        "@sales", [Sales]
    )
VAR CategorizedSales =
    ADDCOLUMNS (
        SummarizedSales,
        "@New Model", IF ( [@rank] <= [Parameter Value], [Model], "Other" )
    )
VAR FilteredSales =
    FILTER (
        CategorizedSales,
        [@New Model] IN VALUES ( 'Models with Other'[Model] )
    )
RETURN
    SUMX ( FilteredSales, [@sales] )

 The TopN number in the above measure is parameterized but can be replaced with an actual number.

Please see the attached pbix.