Build the path in a controller…

$dir_opencart = str_replace('\\', '/', DIR_OPENCART);
$dir_template = str_replace('\\', '/', realpath(__DIR__ . '/../../view/template'));
$data['dir_twig_include'] = str_replace($dir_opencart, '', $dir_template) . '/';

$this->load->view('folder/name', $data);

Then use it in a template…

{% include dir_twig_include ~ 'folder/filename.twig';

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