I need to get the group names in a Group Picker (multiple groups)

[udayasuriyan keerthika]

def groupFlagCf = ComponentAccessor.getCustomFieldManager().getCustomFieldObjectByName("Assigned Group");
log.info(groupFlagCf)
def groupFlag = parent.getCustomFieldValue(groupFlagCf);

log.info(groupFlag)

but i am getting this error [com.atlassian.crowd.embedded.impl.ImmutableGroup@afb7e307].

Can anybody help me in this.