Просто вызовите виды внутри основного вида
public function index()
{
$data['content']['title'] = 'title';
$data['content']['body'] = 'body';
$this->load->view('layout',$data);
}
В views / layout.php
<div id="main_container">
<?php
$this->load->view('header',$content);
$this->load->view('content',$content);
$this->load->view('footer');
?>
</div>
Ex. в views / header.php
<title>.<?php echo $title;?></title>
в views / content.php
<div id="main_body"><?php echo $body;?></div>