Inside those folders are multiple files that I want to display on frontend.
Here is how I managed to get those directories and the pdf files inside them.
                
$upload_dir = wp_upload_dir();
$folder = $upload_dir['basedir'];
// THIS IS TO GET ALL FOLDERS FOUND ON THE DIRECTORY
//In this example, I only want to get the folders under /wp-content/uploads/pdfs
$issues = scandir( $folder.'/pdfs' );
//check if the folders are showing
echo '<pre>';
print_r($issues);
echo '</pre>';
        
                
//THIS IS TO GET ALL THE FILES ON THE FOLDERS I HAVE FETCHED ABOVE
foreach( $issues as $issue ){
$articles = scandir( $folder.'/pdfs/'.$issue );
//check if the files are showing
echo '<pre>';
print_r($articles );
echo '</pre>';
foreach( $articles as $article ){
echo home_url( 'wp-content/uploads/pdfs/'.$issue.'/'.$article ).'<br>';
}
}
        



















