Multiple values against a single ID, how to create a column that checks and records.

Hi CallumJ ,

You can try this:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjQ0VNJRCkktLlGK1QFxjVC5IFnPlNS8ksy0zNQi3GqwmhALAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Doc ID" = _t, Comment = _t]),
    #"Grouped Rows" = Table.Group(Source, {"Doc ID"}, {{"Row", each _, type table [Doc ID=nullable text, Comment=nullable text]}}),
    #"Added Custom" = Table.AddColumn(#"Grouped Rows", "Custom", each _[Row][Comment]),
    #"Expanded Row" = Table.ExpandTableColumn(#"Added Custom", "Row", {"Comment"}, {"Comment"}),
    #"Added Custom1" = Table.AddColumn(#"Expanded Row", "Check", each if List.Contains([Custom], "Identifier") then "Identifier" else "Fail"),
    #"Removed Other Columns" = Table.SelectColumns(#"Added Custom1",{"Doc ID", "Comment", "Check"})
in
    #"Removed Other Columns"

 (copy and paste in a blank query)