A JQL query to link Stories and Epics for multiple initiatives

[Tanya Fraser]

We are trying to run a board that has planned work across multiple projects and linking it to Portfolio using a JQL query. 

I'd like to be able to link a Jira story or Epic to an Initiative and use that to link the work to Portfolio. (Jira tickets are created and then allocated to work and teams)

Is there a query that will link the Epic and the story?

I have tried 

issueFunction in issuesInEpics("'Parent Link' in (XXX-01, XXX-02)")

which will pull all stories

plus

'Parent Link' in (XXX-01, XXX-02)

which will pull the epics.

Ideally I want one query that will pull all Epics and Stories linked to the one query. 

Any help appreciated.