title: Find Value in specific row of multidimensional List
body: <p>I want to find all values (indexes) of a 3D-List in C# (<code>List&lt;List&lt;List&lt;double&gt;&gt;&gt;</code>), but just search in a specific region.</p>
  
  <p>In matlab, this can be done by the following line:</p>
  
  <pre><code>find(my3DList(:,4,:) == 2)
  </code></pre>
  
  <p>This means, searching everywhere where the second dimension is set to 4. The same I want to do in C# using List. I guess the <code>FindAll</code> command could this, but I don't know how to tell the program to fix the second dimension to a specific value.</p>
  
  <p>Can you help?
  Thanks a lot</p>