<?php
$sql_works = "SELECT * FROM works LEFT JOIN otdel ON works.id = otdel.id_type LEFT JOIN exam ON otdel.id_otdel = exam.id_otd ";
$result    = mysql_query($sql_works);
while ($row = mysql_fetch_array($result)) {
    $data[$row['name_work']][$row['name_otdel']][] = $row['name_exam'];
}

echo "<ul class='clop'>";
foreach ($data as $name_work => $otdel_array) {
    echo "<li class='work_title'>" . $name_work . "</li>";
    echo "<ul>";
    foreach ($otdel_array as $otdel_name => $exam_names) {
        echo "<li class='otdel'>" . $otdel_name . "</li>";
        echo "<ul><li class='bg_li'>" . implode('</li><li class="bg_li">', $exam_names) . "</li></ul>";
    }
    echo "</ul>";
}
echo "</ul>";
?>

<?php


$sql_works = "SELECT * FROM works LEFT JOIN otdel ON works.id = otdel.id_type LEFT JOIN exam ON otdel.id_otdel = exam.id_otd ";
$result = mysql_query($sql_works);
while ($row = mysql_fetch_array($result)) {
    $data[$row['name_work']][$row['name_otdel']][] = $row;
}


echo "<ul class='clop'>";
foreach ($data as $name_work => $otdel_array) {
    echo "<li class='work_title'>" . $name_work . "</li>" ;
    echo "<ul>";
    foreach ($otdel_array as $otdel_name => $exam_names) {
        echo "<li class='otdel'>" . $otdel_name . "</li>";
        echo "<ul>";
        foreach ($exam_names as $exam_name){
            echo "<li class='bg_li'>".$exam_name['exam_name'] ." " .$exam_name['TO CHTO NADO'] ."</li>";
        }
        echo "</ul>";
    }
    echo "</ul>";
}
echo "</ul>";
?>