The add-on provides a set of useful JQL functions to filter on the tickets:
1

From the JIRA header, click Issues -> Search for Issues

Search for Issues tab

2

Click Advanced to switch the form to advance search mode using JQL.

Search screen

3

Enter the JQL function

Search screen

4

Click the search icon to run the search. The list of issues appears.

JIRA search screen list view

hqlLinkedIssues

 

hqlLinkedIssuesOf