Need some suggestion about micro sites under same domain separate url

Hi,
I am looking for some solution where main site has its own main menu under same domain, when you click on any department under same domain it has its own main menu. its like microsite under same domain example

www.example.com (has its own main menu like "home, about us, contact us")
www.example.com/about-us (sharing same main menu)
www.example.com/department-1 (has its own main menu like "About, Programs, Faculty")

example main site
https://www.aus.edu/

example sub site
https://www.aus.edu/caad

both are sharing same url.

Plenty of options exist to do this:

1. Database menus driven by location
2. An included view on your main layout which is swapped out as the controller sets it up
3. Separate sites at each folder level (way too extreme, but... it would work)
4. Load the menu view in the controller as HTML and pass to the main view

It seems like #2 above would do what you want.

For example, we use that sort of setup where I code:

PHP Code:

$options = array(
 'page_title'=>'Shipment #'.$id.' Details',
 'view'=>'shipment/shipment_details'
);
$this->load->view('default', $options); 


Where the view is changed with the page load per the needs of the page.  In your case you'd add:

PHP Code:

'menu'=>'caad/menu' 


which then you'd have a folder called caad in your view folder with a menu.php file with the menu for that department.  Like so:

PHP Code:

$this->load->view($view); 


I have system with work perfect with separate sub domain, themes, menu every thing separate, now need microsite under same domain