How to set Spawn location for parent/childs random spawned map pieces

Hello, I need some help with spawning ai on a random tile based map generator.

I made it that every map piece has a spawn box where a random location is picked. The problem that I am having is that I cannot spawn Ai/controllers with this principle. I already used this method for spawning environment and that works great with other child Map pieces.

I was thinking to write all the locations to an array but that is not possible with this.

Can somebody help me out here, Would be very appreciated.