function keyMultiSort(&$array,$key,$reverse = false,$PRiorITy_last = false,$save_key = true,Callable $func = null)
{
    if ($func === null)
    {
        $func = function ($First,$second) use ($key,$reverse,$priority_last)
        {
            if (!isset($first[$key]))
            {
                return ($reverse === false) ? -1 : 1;
            }
            if (!isset($second[$key]))
            {
                return ($reverse === false) ? 1 : -1;
            }

            if ($first[$key] > $second[$key])
            {
                return ($reverse === false) ? 1 : -1;
            }
            if ($first[$key] < $second[$key])
            {
                return ($reverse === false) ? -1 : 1;
            }
            if ($first[$key] === $second[$key])
            {
                return ($priority_last === false) ? 1 : -1;
            }

            return 0;
        };
    }

    if ($save_key)
    {
        uasort($array,$func);
    }
    else
    {
        usort($array,$func);
    }
}

$array = [
    ['foo','bar'],['boo',['goo',['hoo','doo'],['foo','manchu'],['moo',['too','fighters'],['blue kazoo',];

$pairs = [];
$str = '';
foreach($array as $item)
{
    if(!isset($pairs[$item[0]]['count']))
    {
        $pairs[$item[0]]['count'] = 1;
    }
    else
    {
        $pairs[$item[0]]['count']++;
    }
    $pairs[$item[0]]['elements'][] = $item[1];

    if(!isset($pairs[$item[1]]['count']))
    {
        $pairs[$item[1]]['count'] = 1;
    }
    else
    {
        $pairs[$item[1]]['count']++;
    }
    $pairs[$item[1]]['elements'][] = $item[0];
    keyMultiSort($pairs,'count',true);
}

$remove = [];
foreach($pairs as $elm=>$item)
{
    $remove[] = $elm;
    $elements = array_diff($item['elements'],$remove);
    if(empty($elements))
    {
        if (in_array($elm,$remove))
        {
            continue;
        }
        $str .= $elm.PHP_EOL;
    }
    else
    {
        $str .= $elm.' AND ('.implode(' OR ',$elements).')'.PHP_EOL;
    }
    $remove = array_merge($remove,$elements);
}
var_dump($str);

结果：

string(99) "bar AND (foo OR boo OR goo OR moo OR too OR blue kazoo)
foo AND (manchu OR fighters)
hoo AND (doo)
"

它可以优化,取决于目标…