How to list posts that appear in two categories

Question

I would like to list all posts that appear in the current category being viewed that are also posted to a second category.

Example Pictures : LINK

For instance, a listing of the common posts between the Headline category and the Media category if Media is currently being viewed.

Answer 1

I think that all you need is this, from the Codex:

$query = new WP_Query( 
  array( 
    'category__and' => 
    array( 2, 6 ) 
  ) 
);

Where the numbers (2, 6) are your category IDs. Your question does not have enough detail, or enough code, for me to tell you how to implement that inot your page.