I made a blueprint which allows me to open a door when a button is pressed, however i need help in making the door return to it's original state after several seconds have passed.
Add Delay node , then connect it to "Reverse node" and connect it to your MatineeActor reference just as you did with Play Node.
that should apply what you want.
I would use timeline node instead so I will be able to place the door and use it within any level anywhere btw.