The Fibonacci retracement - indicator shows you the Fibonacci retracement levels on the main chart for a user-defined number of bars without having to draw the Fibonacci retracement object.
You can set how many numbers of bars you want to use for the retracement and then the Fibonacci retracement indicator keeps track of the highest highs and lowest lows and then shows you the levels.
When a new high is more recent than a new low the Fibonacci retracement indicator assumes it to be an uptrend and the levels show you where the market price can encounter support when it retraces. When a low is more recent than a high the indicator assumes it to be a downtrend and the lines Show you where the market price can encounter resistance when it retraces.
Here you can download the Fibonacci retracement indicator: https://www.mql5.com/en/code/445