OK, showing a hud for up & down levels is fairly easy. First get yourself the Official Community Guide here
http://forum.thegamecreators.com/?m=forum_view&t=170978&b=21&msg=2025564#m2025564 It has several topics on creating your own custom hud.
Basically you want to place a trigger zone over each layer(level).
Assign a script to it that when the player enters each zone a different hud is displayed. I take it you mean as in "Level 1" or "Level 2"?
Try something like this, remember you will have to make your own hud for each layer and rename them.
:state=0:hudreset,hudx=50,hudy=8,hudimagefine=languagebank\english\gamecore\text\level1.dds,hudname=level1,hudhide=1,hudmake=display
:state=0,plrwithinzone=1:hudshow=level1,state=1
:state=1,plrwithinzone=0:hudunshow=level1,state=0
Now as long as your on level 1 it will show your Level 1 hud.