Create a map of a maze

My first question on a forum on Unreal Engine. Should not be the last one …
I’m creating a game with maze and I’m looking for a way to create a map of each maze. I mean ‘when pushing a key, a map with all part of the maze already visited, will be visible and others part should be hidden’.
I didn’t find tuto to do that.
So i*I Found a solution to create it, but it is a long work with no commun blueprint code:
I create on a widget the map with picture representing each part of wall. when opening the map, in each part of wall I add blueprint to calculate if this part of wall have been seen or not…
I’m sure there is another way more simple to do it, but I can not find it.
Is there somebody to give me a tuto or explain me shortly how to to it??

No idea?