A circa-2017 site plan shows renovations done over the past 3 years. These have added a new Saks, West Wing (indicated in gray) and "jewel box" retail building (in the northeast parking area). Being as how the GALLERIA III section no longer exists, one could surmise that the old "GALLERIA I", "II", "III" and "IV" designations might have been made obsolete.

A contemporary view of the original, vaulted ceiling, section of the GALLERIA complex.
Photo from http://www.vccusa.com/ (VCC General Contractor Construction)

A rendering of the new (and relocated) Saks store. The structure encompasses 2 levels and 198,000 square feet.
Drawing from Saks Fifth Avenue

A rendering of the old (and now reconfigured) Saks, which has been repurposed as inline store and restaurant space.
Drawing from www.simon.com (Simon Property Group)