Create a column with hierarchy information

Hi Powerwoman, another approach:

Output

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjQwsFTSUfJJLUvNUTAAsgwNjEGUUqwOFkkTCyMkSbBCiKQhWKcpPkkzJEmwwpTEkkSwHFgaKmMGlzGCyBhBZKA2g2WMITJAQ2JjAQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [rowNo = _t, description = _t, #"totaling rowNo" = _t, value = _t]),
    ChangedType = Table.TransformColumnTypes(Source,{{"rowNo", type text}, {"totaling rowNo", type text}, {"value", Int64.Type}}),
    R = Function.Invoke(Record.FromList, Table.ToColumns(Table.SelectRows(ChangedType, each not List.Contains({null, ""}, [totaling rowNo]))[[rowNo], [totaling rowNo]])),
    F = (child, optional lvl)=>
        let l = lvl ?? 0,
            a = Record.FieldOrDefault(R, child, 0), // 0 = highest parent (Level 0)
            b = if a = 0 then l else @F(a, l+1)
        in  b,
    Ad_Level = Table.AddColumn(ChangedType, "Level", each F([rowNo]), type text)
in
    Ad_Level