echo $this->Form->input('location');

echo $this->Form->input('location_id', array('type' => 'select', 'options' => $CompanyLocations));

public function add()
{
$user = $this->Users->newEntity();
if ($this->request->is('post')) {
$user = $this->Users->patchEntity($user, $this->request->data);
if ($this->Users->save($user)) {
$this->Flash->success(__('The user has been saved.'));

            return $this->redirect(['action' => 'index']);
        }
        $this->Flash->error(__('The user could not be saved. Please, try again.'));
    }
    $CompanyLocations= $this->Users->CompanyLocations->find('list');
    $this->set(compact('CompanyLocations'));
    $this->set(compact('user'));
    $this->set('_serialize', ['user']);

$this->belongsTo('CompanyLocations');

public function initialize(array $config)
{
parent::initialize($config);

    $this->table('company_locations');
    $this->displayField('location_name');
    $this->primaryKey('location_id');

    $this->belongsTo('Locations', [
        'foreignKey' => 'location_id',
        'joinType' => 'INNER'
    ]);
}

CREATE TABLE IF NOT EXISTS southpac_team.company_locations (
location_id INT NOT NULL AUTO_INCREMENT,
location_name VARCHAR(45) NULL,
PRIMARY KEY (location_id))
ENGINE = InnoDB;

DROP TABLE IF EXISTS southpac_team.users ;

CREATE TABLE IF NOT EXISTS southpac_team.users (
id INT NOT NULL AUTO_INCREMENT,
username VARCHAR(20) NOT NULL,
password VARCHAR(255) NOT NULL,
name VARCHAR(255) NOT NULL,
department INT NULL,
mobile VARCHAR(255) NULL,
email VARCHAR(255) NULL,
extension INT NULL,
lame_number INT NULL,
spa_auth_number VARCHAR(15) NULL,
creation_date DATE NULL,
picture VARCHAR(255) NULL,
employed TINYINT(1) NOT NULL,
location INT NOT NULL,
PRIMARY KEY (id),
INDEX get location_idx (location ASC),
CONSTRAINT get location
FOREIGN KEY (location)
REFERENCES southpac_team.company_locations(location_id)
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;

echo $this->Form->input('company_location_id');

$companyLocations= $this->Users->CompanyLocations->find('list');
$this->set(compact('companyLocations'));

$this->belongsTo('CompanyLocations', [
    'foreignKey' => 'location'
]);

company_locations.location_id > locations.primary_key