MVP design/approach.

bootstrap.php

<?php

$repository = new Repository();
$data = new Data($repository);
$controller = new Controller($data);

$controller->executeAction($_GET['something']);

mvp.php

<?php

class Repository
{
    public function getEntities() {
        // Do database query and return results
    }
}

class Data
{
    protected $repository;
    
    public function __construct(Repository $repository) {
        $this->repository = $repository;
    }
    
    public function getData($requestParam) {
        $entities = $this->repository->getEntities();
        // Do some logic on said entities
        return array(
            'entities' => $entities,
            'otherData' => $otherData
        );
    }
}

class Presenter
{
    public function setData(array $data) {
        // Store data internally
    }

    public function render() {
        // Convert set data into view data and render HTML using it
        return $html;
    }
}

class Controller
{
    protected $data;

    public function __construct(Data $data) {
        $this->data = $data;
    }

    public function executeAction($requestParam) {
        $rawData = $data->getData($requestParam);

        $presenter = new Presenter();
        $presenter->setData($rawData);
        
        return $presenter->render();
    }
}