It's important that you provide some explanation about how you envision your feature. there are simply an infinite amount of solution for "jumping"
but likely only a few that will suit you.
for example is the following jump suitable?
user press "jump", the camera translate into the air using a constant translation value for a predefined amount of time. Once it reached the predefined amount of time it falls down again using the same translation constant until it reaches the base height of the camera. Pressing jump while already jumnping has no effect. The jump is relative to the world, that is the camera is translated by the world y axis during the jump.
If that's suitable, I can build a quick example ( for next week, meanwhile try to experiment