Enemies that follow only up and down

Does anyone know how I can get an enemy or object to follow my character exclusively on the Y axis? I’m creating a boss for my 2D platformer that follows the player upwards and shoots projectiles at them. I can get enemies to chase after the player both from the air and on the ground, but haven’t figured this out yet.

ass

@judae C’mon man, don’t swear…

@“Dan B” , I can only say to follow what @grazer said to do in his tutorial on enemies that follow, but then remove the X- Axis, perhaps?