I'm developing a Dungeon Crawler style game and set a bunch of position objects as a "grid" for the player walk and stored them in a parent object, like a list. So I wanted to use that same list for the enemy moviment but after watching many A* Pathfinding tutorials for weeks I didn't managed to have any ideas of how to solve it since I'm not using a regular 2D grid. Here's a reference.
I took a look at your image, and you do in-fact have a grid. Just because you placed your objects does not mean you can calculate the "grid" for them from the list.
I would suggest you create a function that you call when your level starts.. and it iterates through the children of that object and generates a data structure that allows you to use A* to calculate pathing. You can use the transform.position of each object to determine it's relative placement/adjacency.