app-functions-fn.catalog.php.diff

diff --git a/app/functions/fn.catalog.php b/app/functions/fn.catalog.php
index 21beeb2..982e874 100644
--- a/app/functions/fn.catalog.php
+++ b/app/functions/fn.catalog.php
@@ -1474,7 +1474,12 @@ function fn_get_categories($params = array(), $lang_code = CART_LANGUAGE)
     }
 
     if (!empty($params['max_nesting_level'])) {
-        $condition .= db_quote(" AND ?:categories.level <= ?i", $params['max_nesting_level']);
+        if (!empty($params['parent_category_id'])) {
+            $parent_nesting_level = (int) db_get_field("SELECT level FROM ?:categories WHERE category_id = ?i", $params['parent_category_id']);
+        } else {
+            $parent_nesting_level = 0;
+        }
+        $condition .= db_quote(" AND ?:categories.level <= ?i", $params['max_nesting_level'] + $parent_nesting_level);
     }
 
     $limit = $join = $group_by = '';