code: from llama_index.core.node_parser import HierarchicalNodeParser
  from llama_index.readers.file import FlatReader
  from pathlib import Path
  
  reader = FlatReader()
  document = reader.load_data(Path("files/sample_document1.txt"))
  
  hierarchical_parser = HierarchicalNodeParser.from_defaults(
      chunk_sizes=[128, 64, 32],  
      chunk_overlap=0,              
  )
  nodes = hierarchical_parser.get_nodes_from_documents(document)
  
  
  for node in nodes:
      print(f"Metadata: {node.metadata} \nText: {node.text}")
      
apis: llama_index.core.node_parser.HierarchicalNodeParser.from_defaults llama_index.readers.file.FlatReader
extract_api: [((147, 159), 'llama_index.readers.file.FlatReader', 'FlatReader', ([], {}), '()\n', (157, 159), False, 'from llama_index.readers.file import FlatReader\n'), ((247, 332), 'llama_index.core.node_parser.HierarchicalNodeParser.from_defaults', 'HierarchicalNodeParser.from_defaults', ([], {'chunk_sizes': '[128, 64, 32]', 'chunk_overlap': '(0)'}), '(chunk_sizes=[128, 64, 32], chunk_overlap=0\n    )\n', (283, 332), False, 'from llama_index.core.node_parser import HierarchicalNodeParser\n'), ((188, 222), 'pathlib.Path', 'Path', (['"""files/sample_document1.txt"""'], {}), "('files/sample_document1.txt')\n", (192, 222), False, 'from pathlib import Path\n')]