When performing a WordPress blog migration you sometimes just need to export a certain number of posts vs the entire collection. The easiest way I have found to do this is by performing a custom query using the list of posts by their url slug.
// WPQuery args for slugs - create array fro list https://delim.co/ 'post_type' => 'post', 'post_status' => array( 'publish' ), 'post_name__in' => array( 'slug-1','slug-2' )