A la relation entre l'Element et le Group.

src/Muzich/CoreBundle/Entity/Element.php

    * @ORM\JoinColumn(name="user_id", referencedColumnName="id")
    */
   protected $owner;
+
+  /**
+   * Groupe de l'élément
+   * 
+   * @ORM\ManyToOne(targetEntity="Group", inversedBy="elements")
+   * @ORM\JoinColumn(name="group_id", referencedColumnName="id")
+   */
+  protected $group = null;
   
   /**
    * Cet attribu stocke les enregistrements UsersElementsFavorites liés
   {
       return $this->elements_favorites;
   }
+
+  /**
+   * Set group
+   *
+   * @param Group $group
+   */
+  public function setGroup(Group $group)
+  {
+      $this->group = $group;
+  }
+
+  /**
+   * Get group
+   *
+   * @return Group 
+   */
+  public function getGroup()
+  {
+      return $this->group;
+  }
 }

src/Muzich/CoreBundle/Entity/Group.php

    * @ORM\OneToMany(targetEntity="GroupsTagsFavorites", mappedBy="group")
    */
   protected $tags;
+  
+  /**
+   * Cet attribut contient les enregistrements Element lié 
+   * a ce Groupe.
+   * 
+   * @ORM\OneToMany(targetEntity="Element", mappedBy="group")
+   */
+  protected $elements;
 
   /**
    * 
   {
     return $this->tags;
   }
+
+  /**
+   * Add elements
+   *
+   * @param Element $elements
+   */
+  public function addElement(Element $elements)
+  {
+      $this->elements[] = $elements;
+  }
+
+  /**
+   * Get elements
+   *
+   * @return Doctrine\Common\Collections\Collection 
+   */
+  public function getElements()
+  {
+      return $this->elements;
+  }
 }