Dynamic menu with template

Hi , this is my layout :

Code:

<?= $this->include('templates/header_admin') ?>

<?= $this->renderSection('custom_css') ?>

<?= $this->include('templates/menu_admin') ?>

<?= $this->renderSection('content') ?>
   
<?= $this->include('templates/footer_admin') ?>

<?= $this->renderSection('script') ?>

<?= $this->include('templates/end_html') ?>
 

I want insert a method called for every page (menu is the same for every controllers) , where put i the method to be accessible for every  view ?