Gain/StopLoss Percentage Lines is a quick way to enter your Entry Price in to a stock and track the percentage of gain or loss at the 5% and 10% markers.
Click on the gear settings icon and type in your entry price. The percentage is defaulted to 5%. You can change this to a different percentage at this screen. Note that whatever number you enter will be doubled for the upper and lower lines. For instance, if you want to set your first red line stop loss and green gain line at 2.5%, your two other upper and lower green and red lines will be at 5%.
However, this will not change the text on the tab marker.
To change the tab text, go in to the Pine Editor and change the green text that says "5% Gain" and "5% Loss" to your new percentages.