The stacked-staggered configuration of the BMT Nassau Street Line platforms splits the IND mezzanine levels into halves. The eastern half stretches from Nassau Street to William Street, from the southbound Nassau Street Line platform to the Broadway–Seventh Avenue Line platform. Similarly, the western half of the mezzanine stretches from Nassau Street to Broadway, from the northbound Nassau Street Line to the Lexington Avenue Line platforms. Transferring passengers have to use the third-basement-level IND platform to navigate between both halves of the mezzanine, since the Nassau Street Line's platforms bisect the mezzanine on both the first and second basement levels.