Meta Query Community и или несколько
$args => array(
'relation' => 'AND',
array(
'relation' => 'OR',
array(
'key' => 'title',
'value' => $searchvalue,
'compare' => 'LIKE'
),
array(
'key' => 'author',
'value' => $searchvalue,
'compare' => 'LIKE'
),
array(
'key' => 'genre',
'value' => $searchvalue,
'compare' => 'LIKE'
)
),
array(
'key' => 'rating',
'value' => $ratingvalue,
'compare' => '=',
'type' => 'NUMERIC'
)
)
);
gtamborero