我们可以使用Beautiful Soup库中的find_all()方法来获取所有的子列表，并使用正则表达式来查找下一个较大的点来截断子列表。以下是示例代码：

import re
from bs4 import BeautifulSoup

html = """

  
First
  
Second
  

    
First sub-item one
    
First sub-item two
  
  
Third
  
Fourth
  

    
Second sub-item one
    
Second sub-item two
  

"""

soup = BeautifulSoup(html, 'html.parser')

sublists = soup.find_all('ul')
for sublist in sublists:
    sublist_items = []
    for item in sublist.find_all('li'):
        sublist_items.append(item.text)
        
    # Use regex to find next large point and break out of loop
    if re.search('Third|Fourth', sublist_items[-1]):
        break

print(sublist_items)

此代码将打印子列表 "Second sub-item one" 和 "Second sub-item two"。