ᐅ For exhaust ventilation systems – where should the fresh air intake come from?

We want to ventilate three rooms in our newly built house. We have a chimney and a kitchen exhaust hood with venting, but we are unsure where the fresh air should come from. It is a KfW 70 house:

1) Interior guest bathroom in the basement: Since the bathroom has no light well, we plan to install an exhaust unit here, which will vent through the light well in the adjacent room.

2) Utility room on the ground floor: We actually want a unit with both supply and exhaust air including heat recovery. However, the exterior wall is the main entrance area of the house, so for aesthetic reasons, we do not want an external unit here. Is there such a unit that can be installed, for example, in the upper floor and supply both supply and exhaust air to the room through ducts?

3) Bathroom on the upper floor: Here we will install a standard unit with supply and exhaust air including heat recovery.

For those who have installed exhaust units as well – where do you get the supply air from?
How can the problem in the utility room be solved?

Thanks for your help and ideas!