Hi Saurabh, This can be achieved with the help of distribution while adding reference lines.
To achieve this follow these steps:
1. Open the add reference line dialog box and click on distribution.
2. Then select the value dropdown and change the percentages to 80,90.
3. Change the label as per your need. After that you can select fill above and fill below and select the colour options from the fill dropdown.
Tell me if you want to do something else.