Basically, this map is just the triggers of how to work it, there is a tutorial on this website, but its for people to just take and use quickly, just need to enable everything.
(NB: Did that so it wasn't just you taking and putting in, requires some effort!)
This is for use in leveling as well as an Experience that drops, you can also convert the subtraction in Custom to an add to make the Experience rise.
The Dropping means that at zero, your WHOLE party will do a level up, which is much easier to set up than for each member alone. This is of use in some FF style maps. Once it is at zero, you get an add to the Death Counter for Player #5, (Who should be a computer).
(NB: You could make this add a preserve trigger and save yourself some time, but its not to important to do that)
For each level just have another Death Counter add, and reset of Custom Level.
Hope this is what you wanted.
Remember for leveling up you can convert the Force into Current Player, and set it in either All Players/Force or in every single Player it would effect.