Magento2 CMS Block – How to Display on Product Page

You can find here and explanation of how you can add a product attribute with a custom source model.
The idea is to add a simple attribute like any others (via an install script) and fill in the field source_model with the alias of a model.
This way, when the options are retrieved, the method getAllOptions from the source model class is called. And that method can contain anything.

In your case, you just need to change in the example I linked the method getAllOptions and make it look like this:

public function getAllOptions($withEmpty = false)
{
    if (is_null($this->_options)){
        $this->_options = array();
        $collection = Mage::getModel('cms/block')->getCollection();
        foreach ($collection as $block) {
            $this->_options[] = array('label'=> $block->getTitle(), value => $block->getId());
        }
    }
    $options = $this->_options;
    if ($withEmpty) {
        array_unshift($options, array('value'=>'', 'label'=>''));
    }
    return $options;
}

Your block should extend from product list I believe.

<?php
// app/code/local/Compx/Brandproducts/Block/Recentproducts.php
class Compx_Brandproducts_Block_Brandproducts 
  extends Mage_Catalog_Block_Product_List{ 
  //extends Mage_Core_Block_Template {

  public function getBrandProducts() {
    // call model to fetch data
    $arr_products = array();
    $products = Mage::getModel("brandproducts/brandproducts")->getBrandProducts();

    foreach ($products as $product) {
      $arr_products[] = array(
        'id' => $product­>getId(),
        'name' => $product->getName(),
        'url' => $product->getProductUrl(),
      );
    }

    return $arr_products;
  }
}
?>

And your model file

<?php
// app/code/local/Compx/Brandproducts/Model/Brandproducts.php
class Compx_Brandproducts_Model_Brandproducts 
extends Mage_Catalog_Model_Abstract{
//extends Mage_Core_Model_Abstract {
  public function getBrandProducts() {
  $products = Mage::getModel("catalog/product")->getCollection();
                $products->addAttributeToSelect('*')
                //->setOrder('entity_id', 'DESC')
                ->setPageSize(5);
    return $products;

  }
}

?>