Assuming you're talking about having your character jump while in a top-down perspective, what you're looking for is a jump function with a selective Z axis. You could fairly easily make a code where your character "jumps" (basically, moving up a certain amount and then back down while still facing the direction you were before), but if you're planning to implement some kind of platforming where you can jump onto a box and still have it behave like an obstacle when you're just walking around, then I'm afraid it's unlikely that you'll see that anytime soon.
There is hope, however! Considering that NESmaker is a tool that is going to be used to create Mystic Searches, a game that has top-down selective Z axis jumping, it's very likely we'll see it as an available option sometime in the future.