Tax in
Multiple tax searchs
$tax_query = array( 'relation' => 'OR', array( 'taxonomy' => 'tax', 'terms' => '$tax', 'field' => 'slug', 'operator' => 'IN', ), array( 'taxonomy' => 'tax1', 'terms' => '$tax1', 'field' => 'slug', 'operator' => 'IN', ), array( 'taxonomy' => 'tax2', 'terms' => '$tax2', 'field' => 'slug', 'operator' => 'IN', ), array( 'taxonomy' => 'tax3', 'terms' => '$tax3', 'field' => 'slug', 'operator' => 'IN', ), array( 'taxonomy' => 'tax4', 'terms' => '$tax4', 'field' => 'slug', 'operator' => 'IN', ), );