Hi Katey and Tami!
"East or West Group" is simply a way of specifying those people who have opposite good directions - those with "East" in their good directions are "East Group" and those with "West" are "West Group." The way Marie uses this is to distinguish the groups for people who have spouses, partners, family members, business associates, etc. with opposite good directions. It is basically an abbreviation that makes it instantly clear that the personal energy good directions will be different for these groupings.
Wendy
