$am = $_POST['amount1'];
$ab = $_POST['amount2'];
$args = array(
    'meta_query' => array(
        array(
            'key' => 'pricerub',
            'value' => array($am, $ab),
            'compare' => 'BETWEEN',
        )
    )
);$args = array(
	'post_type'  => 'product',
	'meta_query' => array(
		array(
			'key'     => 'color',
			'value'   => 'blue',
			'compare' => 'NOT LIKE'
		),
		array(
			'key'     => 'price',
			'value'   => array( 20, 100 ),
			'type'    => 'numeric',
			'compare' => 'BETWEEN'
		)
	)
 );
$query = new WP_Query( $args );