Resolution
How can group memberships be updated if they have been changed in the source domain?
fact
Domain Migration Administrator 7.x
fix
There are two different ways to update group membership, depending on how the membership was changed in the source domain.
If members were added to the source group, then the simple task of remigrating the source group with the option 'Replace and Update conflicting accounts' enabled, found in the Naming Conflicts screen of the Group Account Migration Wizard, will add the members from the source group to the target group if the users have been migrated.
If members were deleted from a source group then an additional option would have to be selected. In the Naming Conflicts screen with the 'Replace and Update conflicting accounts' enabled, also enable the 'Remove existing members of groups being replaced'. This option will clear out the group membership of the target group and then reapply the memberships as found in the Source Domain. Use this option with caution. If you have added members that exist only in the target domain, these members will be lost when you remigrate.