MB4 245b: Shared Wells, Ruins, and Bathrooms Between Two Courtyards (376:2-4)

A well is situated on a path adjacent to two chatzerot in a mavui and there are windows opening to the path from each side. How close to the courtyards does the well need to be so both can use it and neither prohibits the other's usage (if no eruv was made)? What if there are doors from each courtyard to the shared path.

Two courtyards with 3 separate ruins with breaches between the ruins situated between the courtyards.