You can find that with somthing like the following
add_shortcode( 'url_path_number', function ( $atts ) {
// use an attribute or the current URL
$a = shortcode_atts( array(
'url' => get_permalink(),
), $atts );
// get the path from the URL
$path = parse_url($a['url'],PHP_URL_PATH);
$parts = array_filter(explode("https://wordpress.stackexchange.com/", $path),function($v) { return $v !== ''; });
// get the last dir of path
return end($parts);
} );
Using the shortcode will return current URL
[url_path_number]
or you can specify the URL
[url_path_number url="https://example.com/page/c/1"]
UPDATE:
to go just after the path, and not use get_permalink()
add_shortcode( 'url_path_number', function ( $atts ) {
$a = shortcode_atts( array(
'path' => $_SERVER['REQUEST_URI'],
), $atts );
$parts = array_filter(explode("https://wordpress.stackexchange.com/",$a['path']),function($v) { return $v !== ''; });
return end($parts);
} );