The function returns the parent of this member.
Apart from measures, every member belongs to a level, and every level belongs to a hierarchy, which defines the parent-child relationships among the members. The system creates an All level (with a single All member), at the highest part of each hierarchy (unless the cube disables the All level for the dimension).
SELECT MEASURES.[%COUNT] ON 0, homed.city.[Elm Heights].PARENT ON 1 FROM patients
To see a picture of the hierarchy used in this example, see the FIRSTCHILD function.