Laravel.io
<?php
class Object extends Eloquent{
    public function objects(){
        return $this->hasMany('Attribute');
    }
}

class Attribute extends Eloquent{
    public function attributes(){
        return $this->hasMany('Value');
    }
}

class Value extends Eloquent{
    public function values(){
        return /* etc. */;
    }
}

Please note that all pasted data is publicly available.