cdm/src/main/java/ucar/nc2/dataset/DatasetConstructor.java
static public Group findGroup(NetcdfFile newFile, Group oldGroup) {
    List<Group> chain = new ArrayList<>(5);
    Group g = oldGroup;
    while ( g.getParentGroup() != null) { // skip the root
      chain.add(0, g); // put in front
      g = g.getParentGroup();
    }

    Group newg = newFile.getRootGroup();
    for (Group oldg : chain) {
      newg = newg.findGroup( oldg.getShortName());
      if (newg == null) return null;
    }
    return newg;
  }
static public Group findGroup(NetcdfFile newFile, Group oldGroup) {
    List<Group> chain = new ArrayList<>(5);
    Group g = oldGroup;
    while ( g.getParentGroup() != null) { // skip the root
      chain.add(0, g); // put in front
      g = g.getParentGroup();
    }

    Group newg = newFile.getRootGroup();
    for (Group oldg : chain) {
      newg = newg.findGroup( oldg.getShortName());
      if (newg == null) return null;
    }
    return newg;
  }
Find the Group in newFile that corresponds (by name) with oldGroup

@param newFile look in this NetcdfFile
@param oldGroup corresponding (by name) with oldGroup
@return corresponding Group, or null if no match.