I have a list of sub-tasks let say sub-task 1, sub-task 2 and sub-task 3, now I have fields design and build on all the sub-tasks.
Now I enter 1 for design and 2 for build on all the sub-tasks, I should see the result of 3 for the design field in the story and 6 for build field.
How can this be achieved, is there a add-on to get pass this issue?