src/Page/ProductCategory.php
public function ChildCategories($recursive = false)
    {
        $ids = array($this->ID);
        if ($recursive) {
            $ids += $this->AllChildCategoryIDs();
        }

        return ProductCategory::get()->filter('ParentID', $ids);
    }
public function ChildCategories($recursive = false)
    {
        $ids = array($this->ID);
        if ($recursive) {
            $ids += $this->AllChildCategoryIDs();
        }

        return ProductCategory::get()->filter('ParentID', $ids);
    }
Return children ProductCategory pages of this category.

@param bool $recursive

@return DataList