I am trying to find the unique area from multiple bounded box generated to find the screen capture by the products in python
You can try threshold the image by colors first (using either HSV threshold, or RGB).
Then having several binary images, you can use Contour Approximation (number 4 on the page) feature, using Douglas-Peucker algorithm. Fill the resulting bounding boxes.
Afterwards, you can subtract resulting binary images from one another to find exact areas of intersections.
Hope it helps!