I recommend looking at our demo report here Stories with Bugs details - Issues - eazyBI Demo Training - eazyBI measure “Hours spent on linked Bugs”. Replace dimension and property “Bugs” in the formula with the name of your imported Issue Link field.
If you have not imported your issue links as a dimension, you can learn how to do that in this community page - Import issue links as dimension
Best wishes,
Elita from support@eazybi.com