Repeated rows to column

Hi Anonymous 

This is my solution. Hope it would be helpful!

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMtE31DdU0lEKLU4tAlKJQACjYnWilYBsx+SSzPw8IMMzD6imBMGAynuWpOaCtBgaQUmouEtqcXJRZgFUc3J+aV5JZl46kFmWmJOZkgjmQJUGZ6bnJeYAGYZgDBKFOs0I4bQkIIBRpDkNhyyqA8tAAEjDZAOK8lNKk0sUfDLzUoHcEI9wQzMDBAOHy2MB", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Date = _t, Field = _t, #"Old Value" = _t, #"New Value" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Date", type date}, {"Field", type text}, {"Old Value", type text}, {"New Value", type text}}),
    #"Filled Down" = Table.FillDown(#"Changed Type",{"Date"}),

    // get the first table for old values   
    #"Removed Other Columns" = Table.SelectColumns(#"Filled Down",{"Date", "Field", "Old Value"}),
    #"Pivoted Column" = Table.Pivot(#"Removed Other Columns", List.Distinct(#"Removed Other Columns"[Field]), "Field", "Old Value"),
    #"Renamed Columns" = Table.RenameColumns(#"Pivoted Column",{{"Description", "Old Description"}, {"Signal", "Old Signal"}, {"Product Line", "Old Product Line"}}),
    
    // get the second table for new values   
    #"Removed Other Columns1" = Table.SelectColumns(#"Filled Down",{"Date", "Field", "New Value"}),
    #"Pivoted Column1" = Table.Pivot(#"Removed Other Columns1", List.Distinct(#"Removed Other Columns1"[Field]), "Field", "New Value"),
    #"Renamed Columns1" = Table.RenameColumns(#"Pivoted Column1",{{"Description", "New Description"}, {"Signal", "New Signal"}, {"Product Line", "New Product Line"}}),
    
    // merge two tables
    FinalTable = Table.NestedJoin(#"Renamed Columns", {"Date", "User", "Action", "Item"}, #"Renamed Columns1", {"Date", "User", "Action", "Item"}, "New Values", JoinKind.FullOuter),
    #"Expanded New Values" = Table.ExpandTableColumn(FinalTable, "New Values", {"New Description", "New Signal", "New Product Line"}, {"New Description", "New Signal", "New Product Line"})
in
    #"Expanded New Values"

Best Regards,
Jing
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