Merging multiple rows into one but only keeping select responses.

Hi GraceJinM,

Bit confused here, based on your example you are taking the max value from each column, not "selecting a row" based on a max value. Well, give this a go.

let
    Source = Table.FromRows(
        {
            {"A", 1, 2, #date(2024, 9, 3)},
            {"A", null, 4, #date(2024, 9, 4)},
            {"B", 4, #date(2024, 9, 2), #date(2024, 9, 3)},
            {"B", 3, null, #date(2024, 9, 5)}
        },
        {"Section N", "Column1", "Column2", "Column3"}
    ),
    GroupRows = Table.Group(Source, {"Section N"}, 
        {{"t", each [Column1=List.Max([Column1]), Column2=List.Max([Column2]), Column3=List.Max([Column3])]}}
    ),
    Expand = Table.ExpandRecordColumn(GroupRows, "t", {"Column1", "Column2", "Column3"})
in
    Expand

I hope this is helpful