its better to include your assets with admin_enqueue_scripts
for your question
add_action('admin_head', 'grup_custom_admin_post_css');
function grup_custom_admin_post_css()
{
$allow_post_types = array('custom_role', 'custom_role_2', 'etc');
$allow_roles = array('post_type', 'post_typ_2');
$current_user = wp_get_current_user();
if (array_intersect($current_user->roles, $allow_roles)) { // do something if user have one of these roles
global $post_type;
if ($post_type && in_array($post_type, $allow_post_types)) {
echo "<style></style>";
}
}
}