From an Initiative item type, how do I pull all epics and children/sub-issues?

[Nikki Bridwell]

I need a query that will return all epics and sub issues from a single work item. We use "Initiative" work item type as our highest level in the hierarchy.  We link Epics using an "Implemented By" link type. This seems like it should be easy, but I am struggling. We previously used Portfolio which had a Parent link field and this worked beautifully.  I do not have the ability to run a plug-in. All help is greatly appreciated.

I want a list from this structure to build my custom project board. 

Initiative

 > Epic 1

     >> Story 1 with subtasks

     >> Story 2 with subtasks

> Epic 2

     >> Story 1 with subtasks

     >> Story 2 with subtasks