You should be able to use the same timeline and vector as this only handles the ‘animation’ of the doors, before this though you could have a boolean variable for each door (Door1Open?, Door2Open?, Door3Open?) and having them set to True after the doors have been opened and False after the doors have been closed. Then before your play your timeline check to see whether or not the boolean is true or false, obviously if it is true you can end the node flow there as nothing more needs to happen (you could maybe print a string saying ‘door already open’ for debug purposes) if the boolean is false you can then continue to play your timeline to open the door
If your not using one single blueprint to control all of this logic it will be a bit more complicated as you will need to do casting and find doors in the scene (They will not be in the order you imagine them to be) You would need to make a copy of each blueprint door (Door1, Door2, Door3 etc) to make casting a bit easier I guess