Moving Stairs: Transform object along Z axis up to players Z position

Hey guys, decided to just play around in UE4, apparently I attempted my first blueprint way out of my skill scope.

I am trying to make a stick/log move up to players feet from below when player approaches it (like a dynamic stairs or something).

Like this:

Here is my logic (probably wrong, if someone is good at it please can you point out what’s not going together? )

However, I don’t know how to activate the event when player approaches it for example: Any Z, but X and Y: current platform location - 50 units for example.

I am not sure why did I add timeline, I wanted to try and set something like Value in timeline according to players Z location and smooth it out but there is no input for it.

Thank You.

Hi man . here an example,
i made an elevator with 4 box, the first is the elevator model, and will be visible and playable.
the initial and final pose, are two cube, that i place at the starting position , and at the final position of the elevator.
I made this instead 2 vectors, because this way you can see where you are placing the elevator, instead make dozen of tests. And you can re-use this elevator , just adjusting the final pose, in the view mode. he will reach different highs.
At the end there is a BOX, its a invisible collision , that when something enter it , will wait a bit, and then
active the elevator.

The elevator have 2 direction , 1, is up to final pose , 0 go to initial pose.
So once he get activation , he check his direction and (LERP) interpolate a position between the two cubes.
When he reach the final pose, he switch the boolean, making him go to the opposite direction.
When the initial pose is reached, he switch back the direction for the next ride, and also switch himself back to off.

You probably want to add a timer, that keep the elevator in place for a couple of seconds.
So you should try to add a gloat likemy LERPER, and make him control a boolean , that get checked before switch direction .