To change this “sub navigation” you could use the WooCommerce filter “woocommerce_get_sections_products“.
The following example code will remove the sub navigation point “inventory”:
function change_navi_function($sections)
{
// remove sub navigation point "inventory"
unset($sections['inventory']);
return $sections;
}
add_filter('woocommerce_get_sections_products', 'change_navi_function');
What you have to do now is either to hook your “change_navi_function” function after the function from the premium plugin and then remove the “Product Vendors” from the “$sections” array. Or you unhook the function from the premium plugin which use the “woocommerce_get_sections_products” filter.