It's an extra function you can link to one of the FN keys. What it does is move a SL or TP line to the high or low of a previous candle. It's an action that happens only once when the linked button is pressed.
Case scenario 1
You have the calc open, and you want to open a buy and place the stop loss exactly 2 pips below the previous candle low. Setting the buffer to 2 and the lookback to 1 will get you that result in one button press.
Case scenario 2
You have a sell trade running and as the trade goes into profit, you want to move the stop loss above previous candles high to take advantage of the trend as long as possible. This is again easily achievable with this function.
Case scenario 3
You have a trade open and you want to place a Partial SL based on the lower time frames, you can to that quickly with this function.
The function will have an action on the instrument that is currently active (calc, partial sl, partial tp, ecc). If none is active it will have an effect on the open trades.
