I use UE 4.17, Matinees have been kinda replaced by the Sequencer. So I’m no Matinee expert.
http://i.imgur.com/j0rOcLU.png
I’d just make a flip flop (this switches between the two different Exec every time you press the mouse button) and play or reverse the Matinee. So if you trigger for example a door, it opens. If you trigger it again, it closes.
http://i.imgur.com/3q3yodr.png
Now, how you get the reference to a Matinee Actor is something you’ll have to look up, I’m sure there are plenty of tutorial videos on youtube for that. I mean, technically you could “get all actors of class” on BeginPlay, but if you have multiple matinee actors you’d have to get the one with the correct index.
http://i.imgur.com/xx8ANN4.png
I use animations for stuff like that, so no external reference involved and animations can be used outside the level. Matinees are saved inside the level, as far as I know.
Of course, this requires a rigged Model.