<?php
$thearray = [];
$terms = get_terms("pa_mymelp");
foreach ( $terms as $term ) {
$categories =  $term->name;
array_push($thearray, $categories);
}

$categoryLines = $thearray;

function buildCategoryTree($categoryLines, $separator) {
    $catTree = array();
    foreach ($categoryLines as $catLine) {
       $path = explode($separator, $catLine);
       $node = & $catTree;
       foreach ($path as $cat) {
           $cat = trim($cat);
           if (!isset($node[$cat])) {
               $node[$cat] = array();
           }
           $node = & $node[$cat];
       }
    }
    return $catTree;
}

function displayCategoryTree($categoryTree, $indent = '') {
    foreach ($categoryTree as $node => $children) {
        echo $indent . $node . "\n";
        displayCategoryTree($children, $indent . '|- ');
    }
}

$categoryTree = buildCategoryTree($categoryLines, '/');

function displayHtmlCategoryTree($categoryTree, $id = null, $pathSeparator = '/', $parents = '') {
    if (empty($categoryTree)) return '';

    $str = '<ul' . (!empty($id) ? ' id="'.$id.'"' : '') . '>';
    foreach ($categoryTree as $node => $children) {
        $currentPath = $parents . (empty($parents) ? '' : $pathSeparator) . $node;
        $thelink = '';
        $opener = 0;
        if (substr_count($currentPath, '/')==5){
        $patterns = array(" ", "/", ".");
        $thelink = 'http://caap.co.nz/?pa_mymelp=' . strtolower(str_replace($patterns, '-', $currentPath));
        $str .= '<li title="' . $currentPath . '">' . '<input class="first" name="' . $currentPath . '" type="checkbox" id="' . $currentPath . '">' . '<label  for="' . $currentPath . '">' . '<a href="' . $thelink .'">' . $node . '</a></label>' .
        /*displayHtmlCategoryTree($children, null, $pathSeparator, $currentPath) .
        */'</li>';}
        else
        {$str .= '<li title="' . $currentPath . '">' . '<input class="first" name="' . $currentPath . '" type="checkbox" id="' . $currentPath . '">' . '<label for="' . $currentPath . '">' . $node . '</label>';
        $str.=displayHtmlCategoryTree($children, null, $pathSeparator, $currentPath);


        }


        }

    $str .= '</li></ul>';
    return $str;
}

    echo displayHtmlCategoryTree($categoryTree, "CategoryTree", '/');


?>