The equasion of the parabola is x = y^2 or y = x^2
In polar coordinates system - it's 2.d/(1-cos(tita))
If you want to simulate a jump - you need an initial y speed, and a x speed (let's say you will keep the x speed a constant, as it'd be a bit simpler).
So now you need an acceleration. The earth's acceleration is g = 9,81
so if your initial speed is 10 (m/s) upwards - after 1 second - it will be 0,19 m/s, and after 1 more second, it will be -8,62.
Anyways, you don't need to set the speed to 9,81 on your map (even if it's pixels, and not meters). You can probobly set it to something easier like 1000.
So what you need to do now is: give the unit some initial speed, and every 0,03-0,05 seconds - reduce that speed by 0,03x1000 - 0,05x1000, AND change the unit's z by the REMAINING speed amount x0,03-0,05. You also need to move the unit towards its jump destination, so futher you need to set its x and y coordinates.
EDIT: So now that you have the theory, what you need to do:
Make a trigger that adds units to a unit group (the units that are going to jump)
Save the jumping unit as a unit [array] variable, with unique index
Save the unit's horizontal and vertical speed in variables, with the unit's index
You could probobly save the angle it's jumping at as well
Run a trigger every 0,03 - 0,05 seconds:
Pick every unit from the jumping group
When you pick a unit: change it's z to ~its z~ + (~the vertical speed~ x ~the frequency of the trigger)
change the unit's position towards the jumping angle, with its horizontal speed
set its vertical speed to ~its vertical speed~ - (~the acceleration you want~ x ~the frequency of the trigger)
If the vertical speed becomes equal to ~negative value of the initial speed~ - remove the unit from the unit group.