//final BugInstanceGroupNode parentGroup = ((RootNode) _root).getChildByBugInstance(parent, depth - 1);
//final BugInstanceGroupNode parentGroup = ((RootNode) _root).getChildByGroupName(GroupBy.getGroupName(_groupBy[depth - 1], parent), depth - 1);
//final BugInstanceGroupNode parentGroup = _groups.get(depth-1 + Arrays.toString(getGroupPath(member)));
if (parentGroup != null) {
final GroupBy groupBy = _groupBy[depth];
groupName = GroupBy.getGroupName(groupBy, member);
final BugInstanceGroupNode childGroup = new BugInstanceGroupNode(groupBy, groupName, parentGroup, member, depth, _project);
addGroupIfAbsent(Arrays.toString(BugInstanceUtil.getGroupPath(parent, depth, _groupBy)), depth, childGroup);
//addGroupIfAbsent(GroupBy.getGroupName(_groupBy[0], parent), depth, childGroup);