Combine 4 M-Codes into 1

let
  Source = Table.FromRows(
    Json.Document(
      Binary.Decompress(
        Binary.FromText(
          "jY/NaoNQEEZfZdCtifNzr/eOu0RNI20TUUMI4iJQS6E0hTYU+vbVdidZdBbf6hw403VBtr0PAcUtkFTESWI9tKeqSEGdB6SYNGYT9FEXVKsTPJS7okkpGjUI2SDSmnA857xxiLe5CTDJCJuo3LVFXTQtrB7bFGgpMwVSjszCQnUH6wzqwy606hzYKWZKFWZV8WrN3KPJOWz/JFUiGIfhuP/1qDmSYfTiDew3m6Zob6d6FrE69pKSkP4Lmj0ly7k3xeV5XA9fw8fn8ATl5fkdqvP323C5QvbyGorhRIXVQn5NAU1MFDOyBH3/Aw==",
          BinaryEncoding.Base64
        ),
        Compression.Deflate
      )
    ),
    let
      _t = ((type nullable text) meta [Serialized.Text = true])
    in
      type table [Transaction_Comment = _t]
  ),
  #"Added Custom4" = Table.AddColumn(
    Source,
    "Custom.4",
    each Text.Trim(
      Text.AfterDelimiter(Text.AfterDelimiter(Text.Upper([Transaction_Comment]), "CHK"), "#")
    )
  ),
  #"Split Column by Character Transition" = Table.SplitColumn(
    #"Added Custom4",
    "Custom.4",
    Splitter.SplitTextByCharacterTransition(
      {"0" .. "9", "A" .. "Z", "-"},
      (c) => not List.Contains({"0" .. "9", "A" .. "Z", "-"}, c)
    ),
    {"CHK#"}
  )
in
  #"Split Column by Character Transition"

How to use this code: Create a new Blank Query. Click on "Advanced Editor". Replace the code in the window with the code provided here. Click "Done". Once you examined the code, replace the Source step with your own source.