How do I reference a specific instance?

i want to make placeable fences similar to stardew valley and i want to change the way the fence connects based in whats next to it. but when this command runs it changes every instance of fence rather than just the one that is overlapping. how do i change just the overlapping fence?

That event looks correct for picking the instance that overlaps sensor 1 or 3, are you sure they're not all overlapping the sensor object?

I just didnt have enough restrictions. got it working perfectly now, thanks!