Power Query Updating a row

vishal140197 

let
    Source = your_table,
    fx_v2_date = (tbl as table) as table =>
        [v2_date = Table.SelectRows(tbl, each [Version Number] = "Version_2"){0}[Date]?,
        v1_change = 
            Table.ReplaceValue(
                tbl, each [Version Number], v2_date, 
                (v, o, n) => 
                    if v = null and o = "Version_1" 
                    then n else v, {"Date"}
            )][v1_change],
    group = 
        Table.Group(
            Source, {"Project Number"}, 
            {{"all", fx_v2_date}}
        ),
    expand = Table.ExpandTableColumn(group, "all", {"Date", "Version Number"})
in
    expand