From the revised core rulebook:

"In order for a unit outside a structure to attack an enemy unit inside a structure, the
enemy unit must be on a space that shows an exit."

Does this imply that as long as a defending unit is in front of ANY exit that it can be shot at, even if the attacking unit is shooting from outside a different exit that the defender is standing in. To give an example, my Blackhawk is standing in a square that is directly in front of a small exit/entrance to a building. Inside the building, 2 spaces away, is Lara. She is standing inside the entrance/exit of the building, albeit a different entrance/exit that the Blackhawk is outside of. Can the Blackhawk target Lara since there is LOS?

JoelVonHelvete said:

I'm going with no on this. the defending unit has to be at the entrance that the attacker is targeting.

I think the picture on page 17 of the revised rules  using the Sturmpioniere is pretty clear about it.

Ah, thanks for pointing that out. I saw that I missed this piece of wording in the example text.

"…the Death Dealers’ space does not have an exit in the
direction of the Sturmpioniere."
 

The wording "in the direction of" answers my question, thanks again.

No Problem. Glad I could help.