When browsing an issue with subtasks, the subtasks panel looks like the below.

There is a "..." dropdown menu with:

• link to issue navgiator with the JQL prefilled to display all subtasks in the issue navigator 
• link to bulk operation for all subtasks

 

 

We would love to have a similar dropdown in the "Issues in epics" panel for epics. Currently there's only the '+' button to add an issue to an epic.