Saving data from a drop down

I created a menu page where it has a drop down menu with a list of menus from the database and it also has a textbox to enter new menus.

The problem I'm having is that I can't seem to figure out how to save my dropdown. So for example I have a menu called "About Us" in the drop down list and I want to create a new menu called "Team", and "Team" is a child of "About Us"

So in my table I would have something like this

id | parent | title
------------------------
1 | NULL | About Us
2 | 1 | Team

Menu Controller

Code:

function create()
    {
        $update_id = $this->uri->segment(3);
        $submit = $this->input->post('submit', TRUE);

        if($submit == "Submit"){
            //person has submitted the form
            $data = $this->get_data_from_post();
        }else{
            if(is_numeric($update_id)){
                $data = $this->get_data_from_db($update_id);
            }
        }

        if(!isset($data)){
            $data = $this->get_data_from_post();
        }


        //$titles = array();

        $query = $this->get('title');
        foreach($query->result() as $row){
            $titles[] = $row->title;
        }

        $data['titles'] = $titles;

        $data['update_id'] = $update_id;

        $data['view_file'] = "create";
        $this->load->module('templates');
        $this->templates->admin_template($data);
    }

    function submit()
    {
        $this->load->library('form_validation');

        $this->form_validation->set_rules('title', 'Title', 'required|xss_clean');

        if($this->form_validation->run($this) == FALSE){
            $this->create();
        }else{
            $data = $this->get_data_from_post();

            //figure out wat the url is
            //$data['url'] = url_title($data['title']);

            $update_id = $this->uri->segment(3);

            if(is_numeric($update_id)){
                $this->_update($update_id, $data);
            }else{
                $this->_insert($data);
            }

            redirect('menus/manage');
        }
    }

    function delete($update_id)
    {
        $this->_delete($update_id);

        redirect('menus/manage');
    }

function get($order_by) {
$this->load->model('mdl_menus');
$query = $this->mdl_menus->get($order_by);
return $query;
}

create.php view

Code:

<div class="row">
    <div class="col-md-12">
        <h2>Create Menus</h2>  
        <h5>Welcome Jhon Deo , Need to make dynamic. </h5>
    </div>
</div>

<hr />

<?php
    echo validation_errors("<p style='color: red;'>", "</p>");
    echo form_open('menus/submit/'.$update_id);
?>
<div class="row">
    <div class="col-md-12">
        <form role="form">
        <div class="form-group">
        <select name="menus">
            <?php
                foreach($titles as $title){
                    
                    echo "<option value=".$title.">".$title."</option>";
                }
            ?>
            </select>
            
            
        </div>

            <div class="form-group">
                <label>Title</label>
                <!-- <input class="form-control" /> -->
                <?php
                    $data = array(
                                'name' => 'title',
                                'id' => 'title',
                                'value' => $title,
                                'class' => 'form-control',
                            );

                    echo form_input($data);
                ?>
            </div>

            <?php
                
                $data = array(
                    'name' => 'submit',
                    'id' => 'submit',
                    'value' => 'Submit',
                    'class' => 'btn btn-success',
                    'style' => 'width: 100%',
                );

                echo form_submit($data);
            ?>
        </form>
    </div>
</div>
<?php    
    echo form_close();
?>

If there is any other information you need me to give please let me know