team showcase search by title only

bytitle.php

<?php

add_action( 'pre_get_posts', 'team_search_by_name_only' );
function team_search_by_name_only( $query ) {

	global $wp_query;

	if ( ! is_admin() && in_array ( $query->get( 'post_type' ), array( 'tshowcase' ) ) && $query->is_search() ) {
		$query->set( 'meta_key', '_ts_lastname' );
		$query->set( 'meta_value', $query->get( 's' ) );
		$query->set( 'meta_compare',  'LIKE' );

		unset( $query->query_vars[ 's' ] );

		return;
	}
}