The Bollinger MTF is the multi-timeframe version of the Bollinger Bands, and its main use is in intraday trading. Multi-timeframe means that the indicator is calculated in a separate timeframe than that which is displayed in the chart. With the standard Bollinger band indicator, displaying an hourly Bollinger band in a 5-minute timeframe would not be possible – this is the point at which the MTF becomes useful. BollingerMTF can only be used for display in the chart and cannot be applied/implemented in TradersYard X Script.
The image shows a 5-minute chart with a 60-minute Bollinger band