Topic campus

// WP_Query arguments
$args = array(
	'post_type'              => array( 'speakers' ),
	'nopaging'               => true,
	'posts_per_page'         => '-1',
	'order'                  => 'ASC',
	'tax_query'              => array(
		array(
			'taxonomy'         => 'topic',
			'terms'            => 'test',
		),
	),
);

// The Query
$query = new WP_Query( $args );