Multiply two columns based on column header name

Hi Mic1979, check this. This will also work if you have more than 1 % or € column (they will be multiplied all together)

Output

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlVV0lFKBGJDAzBhYKAUqxMNZIDEk4DYCCRuChM3AosnA7ExTD1QIhYA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Column1%" = _t, Column2 = _t, #"Column3€" = _t, Column4 = _t]),
    ChangedType = Table.TransformColumnTypes(Source,{{"Column1%", Percentage.Type}, {"Column3€", type number}, {"Column4", type number}}),
    Ad_Multiplied = Table.AddColumn(ChangedType, "Multiplied % and €", each
        [ a = Record.ToList(Record.SelectFields(_, List.Select(Record.FieldNames(_), (x)=> List.Contains({"%", "€"}, x, (y,z)=> Text.Contains(z, y))))),
          b = Expression.Evaluate(Text.Combine(List.Transform(a, (x)=> Number.ToText(x, "G", "en-US")), "*"))
        ][b], type number)
in
    Ad_Multiplied