It works by taking the range of the last day, multiplying it by 0.38 and 0.62 a projecting them from the opening of the current day, both in the up and down directions. You can configure it to use the range of the day, the week, or whatever. You can also hide other values and display only in the current day, or current week, or whatever.
This way you can easily visualize the areas of .
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.