Hello,
here is a quick example of one possibility to do it : i created a thirdperson project, i added four trigger in level map then dragged them in level blueprint to have their references, then created 3 booleans. then did this and when player goes on one of the first triggers it checks if 3 are ok or not and react in the right way. the fourth one clears all.
edit : to have the first one : select character in map, then right click and type beginoverlap to have it.