The point is here that you have to know when the player enters or leave the trigger.
Assume that you only want to have one large trigger which overs the whole “outside of the level” area.
Then you need to know when the player enters it and if the player have not leaved the trigger then game over.
In any case you need a status which tells you if the player has left that area.
So create a bool variable hasPlayerEntered
OnBeginOverlap => Set hasPlayerEntered=true => Delay 2 => Branch hasPlayerEntered=true => GameOver
OnEndOverlap => Set hasPlayerEntered=false
If the player enters the area you know this now. The delay runs and if the player leave the area during the delay the variable is set to false and nothing happens.
This is the most simple solution I can think of. If anyone has a simpler solution for that please I’m also interested in this.