Hi,

this reply is inspired by the article –

to obtain this:

You need:

- first create a query in which you remove duplicates and rank 

let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjQ2NjE1U9IBMkxMQZRSrA6qKIgywhA1B1LG5ImaQ0QtUG2Dilqi2oYqGgsA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Van number" = _t, #"Calling ID" = _t, Index = _t]),
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Van number", Int64.Type}, {"Calling ID", Int64.Type}, {"Index", Int64.Type}}),
#"Removed Columns" = Table.RemoveColumns(#"Changed Type",{"Index"}),
#"Removed Duplicates" = Table.Distinct(#"Removed Columns", {"Calling ID"}),
#"Grouped Rows" = Table.Group(#"Removed Duplicates", {"Van number"}, {{"AllRows", each _, type table [Van number=nullable number, Calling ID=nullable number]}}),
RankFunction = (tabletorank as table) as table =>
let
SortRows = Table.Sort(tabletorank,{{"Calling ID", Order.Ascending}}),
AddIndex = Table.AddIndexColumn(SortRows, "Rank", 1, 1)
in
AddIndex,
//Apply that function to the AllRows column
AddedRank = Table.TransformColumns(#"Grouped Rows", {"AllRows", each RankFunction(_)}),
#"Expanded AllRows" = Table.ExpandTableColumn(AddedRank, "AllRows", {"Calling ID", "Rank"}, {"Calling ID", "Rank"})
in
#"Expanded AllRows"

- then in the original query (the one where you have duplicates) you have only to merge the second one:

 let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjQ2NjE1U9IBMkxMQZRSrA6qKIgywhA1B1LG5ImaQ0QtUG2Dilqi2oYqGgsA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Van number" = _t, #"Calling ID" = _t, Index = _t]),
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Van number", Int64.Type}, {"Calling ID", Int64.Type}, {"Index", Int64.Type}}),
#"Removed Columns" = Table.RemoveColumns(#"Changed Type",{"Index"}),
#"Merged Queries" = Table.NestedJoin(#"Removed Columns", {"Calling ID"}, RemovedDuplicates, {"Calling ID"}, "Table (3)", JoinKind.LeftOuter),
#"Expanded Table (3)" = Table.ExpandTableColumn(#"Merged Queries", "Table (3)", {"Rank"}, {"Rank.1"})
in
#"Expanded Table (3)"

and that's done