Story or Task relationship to Sprints-Fit with Epic/Story hierarchy

[Ashley Silver]

It appears to be "common wisdom" that a (Jira) Story should be accomplished in single sprint.  Does this mean that a complex task that has integrity still needs to be broken down until all the pieces fit can each fit a sprint?

Does this imply that for a Unit of Deliverable value ("Epic"), there can be huge complexity between a (Jira) Epic and its (Jira) Stories? 

If so how do we manage the logical continuity between the master Epic, and the Stories that are required to materialize it?  To my mind it implies levels of Epics within Epics or Stories within Stories? 

Or is everything reported/managed in Jira as just a two-level hierarchy?

(I assume Sub-tasks are out of the picture as they cannot earn story points, and tasks are for practical purposes (maybe a different Workflow) the same as stories.)