Currently we have a couple of options:
If there are chapter marks in the Video, you can
- in Std View just "Right Click --> Jump" SubMenu to select the chapter you want
- in TheaterView you can "up arrow" till you get to Chapter then "Left / Right arrow" to skip though
MC will also bookmark so you start playback where you left off.
On stuff like BD you also don't get Chapter "names" just Chapter 1, 2 etc
If you don't have chapter marks in the Video then you are currently out of luck.
See this thread about a request to support Chapter sidecar files:
http://yabb.jriver.com/interact/index.php?topic=100345.0