title: Linq filter List<string> where it contains a string value from another List<string>
body: <p>I have 2 List objects (simplified):</p>
  
  <pre><code>var fileList = Directory.EnumerateFiles(baseSourceFolderStr, fileNameStartStr + "*", SearchOption.AllDirectories);
  
  var filterList = new List&lt;string&gt;();
  filterList.Add("ThisFolderName");
  filterList.Add("ThatFolderName");
  </code></pre>
  
  <p>I want to filter the fileLst to return only files containing any of folder names from the filterList. (I hope that makes sense..)</p>
  
  <p>I have tried the following expression, but this always returns an empty list.</p>
  
  <pre><code>var filteredFileList = fileList.Where(fl =&gt; fl.Any(x =&gt; filterList.Contains(x.ToString())));
  </code></pre>
  
  <p>I can't seem to make sense of why I am getting nothing, clearly I am missing something, but I have no idea what.</p>
  
  <p>[EDIT]</p>
  
  <p>Ok, so it appears I should have been clearer in my question, I was trying to search for files in my fileList with a substring containing string values from my filterList. I have marked the answer below for those who are trying to do a similar thing.</p>