This is a very simple script that I couldn't find on TradingView yet. Look at this indicator how you want (band, cloud, ma's) and create your own settings, I did not test it.
Normally, average calculates the average(middle) of the highest point of a given period and the lowest point of that same period.
Here I use two separate periods, one for highest, a different one for lowest. That's it :)
Let me know if it's useful to you, I appreciate your comments.