Dynamic row numbers based on Rank Column

Well i got a solution on my own..but its not by using DAX..
Its magic power query.

Solution:-

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("bdFNCoAgEIbhu8xaMJ0iW1ba3xXE+18jUSonvp08DDO8GCPNpKjXVtvOuPycKKlIi0RTcJXIBb1EWzCgyQ3t3BEeEoeCJzp0/Q7VSzWJH3VNEqMklks9wiCxTWKUxCjpxbFJYpT0Yf6QdAM=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [SBU = _t, Date = _t, Count = _t]),
    #"Changed Type1" = Table.TransformColumnTypes(Source,{{"Count", Int64.Type}}),
    #"Sorted Rows" = Table.Sort(#"Changed Type1",{{"Date", Order.Ascending}, {"Count", Order.Descending}}),
    #"Changed Type" = Table.TransformColumnTypes(#"Sorted Rows",{{"Count", Int64.Type}, {"Date", type date}}),

    Partition = Table.Group(#"Changed Type", {"Date"}, {{"Count", each Table.AddIndexColumn(_, "Index2",1,1), type table}}),
    #"Expanded Count" = Table.ExpandTableColumn(Partition, "Count", {"SBU", "Count", "Index2"}, {"SBU", "Count.1", "Index2"}),
    #"Changed Type2" = Table.TransformColumnTypes(#"Expanded Count",{{"SBU", type text}, {"Count.1", Int64.Type}, {"Index2", Int64.Type}})
in
    #"Changed Type2"

Thanks for the help Anonymous