Please go thorugh the below URL for entire soultion.
http://community.powerbi.com/t5/Desktop/DAX-Grouping-on-multiple-columns-and-the-count/m-p/282216#M125604
http://community.powerbi.com/t5/Desktop/DAX-Grouping-on-multiple-columns-and-the-count/m-p/282216#M125604