Multiple Buildings, different sites. Sharing underground

Hi there. I would like to have a recomendation on how to register three different projects that are being built together in the same construction site. We are using LEED for new construction pursuing different levels of certification Despite the sharing of the underground, each of the buildings are independently owned by different landlords and are located at separate municipal sites. However, there is a physical connection through undergrounds, which will affect indoor air quality during construction and other subsequent construction issues during construction phase and later during operation. Each of these projects have their own parking calculations and square footage meaning that each of these three buildings, will have different gross footage and independent site boundary. Do these three buildings need to be registered on their own or should they be registered as multiple buildings "On-Campus" creating a common LEED site boundary? Thank you for your guidance