First Chapter mark

Help! Under huge deadline!

In my project I have 5 timelines and about 30 chapter points on each. When the
DVD is playing and I am skipping around the chapter points, if I try to hit back
when I'm on the first chapter point (the start of that timeline) it takes me
back to another timeline. Is there a way to have chapter skipping functionality
in a timeline, but set it so that it cannot go to another timeline if I hit back
right at the start? Or can I set it so that if it does need to go somewhere, it
goes to the menu?

If you wire the timelines directly the behavior is correct. You would have to
enter the timeline indirectly from a playlist, i.e. your menu goes to the
playlist and the playlist refers to the timeline. you can then set the timeline
itself to return to the menu.