I ended up answering my own question by using the following code
add_filter( 'template_include','include_filter_template_function', 1 );
function include_filter_template_function($template_path ) {
$template_path = plugin_dir_path( __FILE__ ) .'filter.php';
return $template_path;
}
and checking the params on that page. I’m sure there is a more elegant way to do this but it works for me. 🙂