This indicator was originally developed by Vitali Apirine (Stocks & Commodities V. 37:5 (April, 2019): Adaptive Exponential Moving Average).
This is his second modification of Kaufman Moving Average. In essence, the idea remains the same as in the previous (https://www.tradingview.com/script/urJFGIcv-Adaptive-Moving-Average/): the smoothing constant is calculated as a special ratio between the current price and highest/lowest prices for a given period.
In combination with EMA you can obtain a trading system based on double crossovers: