Traversing back to parent node in xpath - asp.net

Question

Below is my HTML
<ul><li class="section">BROADCASTING</li>
<ul>
<li class="subsection"></li>
<li class="circle">STATION BREAK</li>
<li class="circle">Labor pains, hunger pangs</li>
<li class="circle">Wake-up call for Dream Team</li>
<li class="circle">News crew turns rescuer</li>
<li class="circle">Chopper safety had been challenged</li>
<li class="circle">Nielsen adds Dayton..</li>
<li class="circle">Mondale watch</li>
<li class="circle">Those 70s clearances</li>
<li class="circle">Oscar goes to ABC</li>
<li class="circle">Hearst-Argyle gives a green light</li>
<li class="circle">Finding Geena Davis</li>
<li class="circle">Syndication Wrap-up</li>
<li class="circle">CBS TV news pioneer dies at 86</li>
<li class="circle">New York anchor remembered</li>
<li class="circle">News sharing in West Virginia</li>
<li class="circle">News dropping in Orlando</li>
<li class="subsection">Null</li>
<li class="circle">GET WITH THE PROGRAM</li>
<li class="subsection">PEOPLE'S CHOICE</li>
<li class="circle">Syndication as branding</li>
</ul>
</ul>
Now i want to seperate sections and subsections and get the url inside subsections.
i have go to the each sections
Now as per the HTML structure, section is in seperate li which closes before subsection opens, so once i have reached section, i have to move back to ul and then have to continue to get subsection
However when i try ../ to go back to the ul (the one before section), it says ivalid token
This is what i tried to come back to the parent one.
HtmlNodeCollection sections = doc.DocumentNode.SelectNodes("//ul/li[#class='section'][contains(text(), 'BROADCASTING')]../ul");
but this does not works
Can anyone tell me where i am going wrong, it will be a kind help.

Answer 1

You need to change your xpath expression a bit:
var subsections = doc.DocumentNode.SelectNodes("//ul/ul[preceding-sibling::li[#class='section' and .='BROADCASTING']]/li[#class='subsection']");
It searches for <ul> inside <ul> that has <li class="section">BROADCASTING</li> as a previous sibling, and then searches for <li class="subsection"> inside it.
So the code above selects all the subsections under BROADCASTING section.
Hope this helps.