public function GroupsMenu()
    {
        if ($this->Parent() instanceof ProductCategory) {
            return $this->Parent()->GroupsMenu();
        }
        return ProductCategory::get()
            ->filter('ParentID', $this->ID);
    }
public function GroupsMenu()
    {
        if ($this->Parent() instanceof ProductCategory) {
            return $this->Parent()->GroupsMenu();
        }
        return ProductCategory::get()
            ->filter('ParentID', $this->ID);
    }
public function GroupsMenu ( ) { if ( $ this -> Parent ( ) instanceof ProductCategory ) { return $ this -> Parent ( ) -> GroupsMenu ( ) ; } return ProductCategory :: get ( ) -> filter ( 'ParentID' , $ this -> ID ) ; }
Recursively generate a product menu, starting from the topmost category.

@return DataList
Recursively generate a product menu starting from the topmost category .