Complex sentence: The Law Brook or Postford Brook is a tributary of the Tillingbourne in Surrey, thus sub-tributary of the Wey and sub- sub-tributary of the Thames notable in its own right chiefly for its industrial heritage.
Split into simpler sentences: The Law Brook or Postford Brook is a Surrey stream, a tributary of the Tillingbourne which in turn flows into the River Wey. It is notable in its own right chiefly for its industrial heritage.