Here is my hit:
>>> from BeautifulSoup import BeautifulSoup
>>> html = """<folder name="folder1">
<folder name="folder2">
<bookmark href="link.html">
</folder>
</folder>
"""
>>> bookmarks = soup.findAll('bookmark')
>>> [p.get('name') for p in bookmarks[0].findAllPrevious(name = 'folder')]
[u'folder2', u'folder1']
The key difference from @eumiro's answer is what I use findAllPreviousinstead findParents. When I tested the @eumiro solution, I found that it findParentsonly returned the first (immediate) parent, since the name of the parent and grandparents are the same.
>>> [p.get('name') for p in bookmarks[0].findParents('folder')]
[u'folder2']
>>> [p.get('name') for p in bookmarks[0].findParents()]
[u'folder2', None]
, - .
>>> html = """<folder name="folder1">
<folder_parent name="folder2">
<bookmark href="link.html">
</folder_parent>
</folder>
"""
>>> soup = BeautifulSoup(html)
>>> bookmarks = soup.findAll('bookmark')
>>> [p.get('name') for p in bookmarks[0].findParents()]
[u'folder2', u'folder1', None]