code: def level_grouper(text, getreffs, level=None, groupby=20):
      
      if level is None or level > len(text.citation):
          level = len(text.citation)
  
      references = [ref.split(":")[-1] for ref in getreffs(level=level)]
      _refs = OrderedDict()
  
      for key in references:
          k = ".".join(key.split(".")[:level-1])
          if k not in _refs:
              _refs[k] = []
          _refs[k].append(key)
          del k
  
      return [
          (
              join_or_single(ref[0], ref[-1]),
              join_or_single(ref[0], ref[-1])
          )
          for sublist in _refs.values()
          for ref in [
              sublist[i:i+groupby]
              for i in range(0, len(sublist), groupby)
          ]
      ]
docs: Alternative to level_chunker: groups levels together at the latest level
  
      :param text: Text object
      :param getreffs: GetValidReff query callback
      :param level: Level of citation to retrieve
      :param groupby: Number of level to groupby
      :return: Automatically curated references