Should i use big one scene, or divided scene for AI Navigation ?

so I have a small town which is divided into 4 scenes. but the problem I'm facing is, how can I make my ai walk to destination in different scene without teleporting (because now I'm implementing the teleport method).

should I combine my 4 small town scenes into one? I'm stuck here.

I want my AI to be able to navigate like in the Stardew Valley game. how did he accomplish that ? did he have 1 big scene ? or divided scene ?