Plot Fibonacci levels between two inputs

I moved your question out of the "Frequently Asked Questions" and into the "Chart Studies" topic. I also updated the title of your question to include the full name instead of the abbreviation. Both of these changes will make it easier for the rest of our viewers to locate this solution using the search function.

You did not state which direction you wanted the Fibonacci levels to be computed so I had to pick one. I included the three most common Fibonacci levels as well as the zero and 100% levels. Once you see how the code is structured you can add any additional lines you want. I also included user inputs to adjust the multiplier for each of the three Fibonacci levels.

Screenshot below shows how this looks on the chart. The screenshot includes a comment showing where I have added a hand drawn Fibonacci retracement to validate the levels are computed correctly.

input priceHigh = 100.0;
input priceLow = 50.0;
input fibOne = 23.8;
input fibTwo = 50.0;
input fibThree = 61.8;
def range = priceHigh - priceLow;
plot fibZero = priceLow;
plot fibLevelOne = priceLow + (range * fibOne * 0.01);
plot fibLevelTwo = priceLow + (range * fibTwo * 0.01);
plot fibLevelThree = priceLow + (range * fibThree * 0.01);
plot fib100 = priceHigh;