Not sure if this is possible, but I was wondering if there's a way you can use JQL to pull all child issues (epics, stories, sub-tasks, bugs, etc) of not just one initiative, but all initiatives of a project.
The reason I need this is because a project manager that I work for wants to use a rich filter dashboard to display all issues associated to an Initiative issue of choice and query down to specifics with the use of rich filter gadgets (see below):

In the example above, this rich filter dashboard works off of this query:
issuekey in childIssuesOf(RYOTGL-923)
I don't want to just restrict the dashboard to look at only one initiative (RYOTGL-923), but I want to be able to look into any initiative issue chosen. I need to see if there's a way that I can edit the "Project Selector" controller gadget that would allow the user to select from a list of initiatives from a project, and still maintain the functionality of the "Project Issues" dashboard, which displays the filter results of the query the dashboard works off of.
If there was even a way that the query above could be something like:
issuekey in childIssuesOf(all Initiative issues in RYOTGL)
, and then use the key dynamic filter for the "Project Selector" gadget to choose from any of the initiatives, then that would completely fulfill my use case.
Any help is much appreciated!