Instead of using fixed levels, this version of double smoothed stochastic is using “stripped” Laguerre filter for levels and trends.
Stripped Laguerre filter is showing intermediate steps performed by Laguerre filter as “levels” that can then be used as support/resistance (or overbought/oversold) levels (depending on the trading style) of the underlying indicator. In this case a double smoothed stochastic is used for the basic calculation.