Title: Hide Title can be set, but need not be displayed
Filter▲▼
Show all Children of: Current Item Current Root Item Current Parent Item
Starting Level: Level to start testing items for inclusion
For Depth: unlimited Relative to the first Filtered item found
Fallbacks▲▼
If "Children of" is Current Root / Parent Item, and no ancestor exists : Switch to Current Item, and Include Parent... & its Siblings If Current Root/Parent and no ancestor exists
If "Children of" is Current Item, and current item has no children : Switch to Current Parent Item, and Include Parent... & its Siblings
Output▲▼
Hierarchical Flat
Include Parent... & its Siblings Include Ancestors Title from Parent Only if the "Children of" Filter returns items
Title from "Current" Item Lower priority than "Title from Parent"
Change UL to OL: Top Level Sub-Levels
Note that since WP v3.6 does it automatically, "Hide Widget if Empty" is ON for this demo.