This is a modified Bollinger Bands® displaying the upper and lower borders of the price deviation from МА calculated considering the average volatility of the symbol according to ATR indicator. The internal MintCream-colored indicator channel stands for Bollinger Bands, while the pale light green and pale pink borders are formed by ATR by deviation from the channel.
The indicator uses the classes of SmoothAlgorithms.mqh library (copy it to <terminal_data_folder>\MQL5\Include). The use of the classes was thoroughly described in the article "Averaging Price Series for Intermediate Calculations Without Using Additional Buffers".
Fig.1. XMA_BBxATR_Cloud indicator
Translated from Russian by MetaQuotes Software Corp.
Original code: https://www.mql5.com/ru/code/16881
The Expert Advisor is based on moving averages crossing.Yaanna_HTF
The Yaanna indicator with the timeframe selection option available in the input parameters.