Theory :

According to Vitali Apirine's article "Higher Highs & Lower Lows,"  in in February 2016 issue of TASC, the momentum indicator-based system HHLLS (higher high, lower low stochastic) can help to spot emerging trends, define correction periods, and anticipate reversals. As with many indicators, HHLLS signals can also be generated by looking for divergences and crossovers. Because the HHLLS is an oscillator, it can also be used to identify overbought & oversold levels.

Usage :

You can use the color change of the fill zone (ie: the crosses of the two values) as signals