Creating lights on douple layered map

Im somewhat new to the engine but i have some Unity & coding background

currently im just playing around with tools but i came to this problem, while rendering my map.

i have two landscapes on top of eachothers on different layers, i dont know why i did that, just for laughs i guess,
anyways the upper landscape cant cast shadow on bottom one or it will be too dark.
the upper layer (level?) is not initialy loaded but just when you hit the trigger which takes you there.

Can i someway build the lights on both levels separately? - pic for those who understandably didnt get it

it seems i always have unbuild light objects no matter how i try to bake em

is there some simple solution im just not seeing?

thank you

Building only lightning (all levels) does not calculate shadows for NewMap4, the one not loaded on startup and i cant find a way to bake shadows on that level without effecting the others.

what should i do to make that “100-2000 shadows need to be rebuild” would go away, it even shows up if i dont go to NewMap4 loading trigger