One important feature for doing true enterprise backlog management is to be able to prioritize a part of it (independent from other parts).
This is often the case when you have multiple product owners within the same large project.
Start with going to items in a hierarchy, right-click a sub project and select View selected only:
Now, go to "Items prioritized" and select priority from the column:
Note that it is not possible to prioritize parent items. If an item has been broken down you can only prioritize the child items.
While in the Product backlog though you can tag items as Epics. This will allow for the prioritization of those flagged items even if they are parents.