As a Product Owner (and ScrumMaster) I would like the ability to sort a sprint backlog in plan-view without affecting rank (and without affecting backlog) by the following
Must have

• by epic
• by story point value (highest to lowest)

Nice to have

• by fixversion
• by ticket type
• by priority

Not required but...

• when sort by story points, if stories are in the same epic and values are the same, group those stories together