tax query
$tax_query = array( 'relation' => 'AND', array( 'taxonomy' => 'category', 'terms' => 'whitepaper', 'field' => 'slug', 'operator' => 'AND', ), array( 'taxonomy' => 'sector', 'terms' => 'retail-banking', 'field' => 'slug', 'operator' => 'AND', ), );