How to find duplicate values in one column while another column has different values?

Hi JonKho ,

Based on the information you have provided, it appears that you are trying to identify records that do not have duplicate values in the [merged columns]?
If yes, please refer to the m code below to group and count the table by [Merge Columns] and then filter the count to find the matching records.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjSwNDNW0gHSBmASyAMxY3UgUoYoUobIUiBdRghdRsRJgQw0RhhoTEAqFgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Controller_Node_Id = _t, BarCode = _t, #"Merged Column" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Controller_Node_Id", Int64.Type}, {"BarCode", Int64.Type}, {"Merged Column", Int64.Type}}),
    #"Grouped Rows" = Table.Group(#"Changed Type", {"Merged Column"}, {{"Count", each Table.RowCount(_), Int64.Type}, {"Data", each _, type table [Controller_Node_Id=nullable number, BarCode=nullable number, Merged Column=nullable number]}}),
    #"Expanded Data" = Table.ExpandTableColumn(#"Grouped Rows", "Data", {"Controller_Node_Id", "BarCode"}, {"Controller_Node_Id", "BarCode"})
in
    #"Expanded Data"

Best Regards,
Gao
Community Support Team

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If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!

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Hi,

Write this calculated column formula

Column = if(CALCULATE(DISTINCTCOUNT(Data[Controller_Node_Id]),FILTER(Data,Data[BarCode]=EARLIER(Data[BarCode])))>1,"Duplicate","Unique")

Hope this helps.