Issue sending parent Id through recursive function

internal static class FilterService
{
    internal static IEnumerable<TableElement> FilterStructureElements(
      IEnumerable<PdfStructureElement> elements,
      Func<PdfStructureElement, bool> predicate,
    int parentId = 0)
        {
            foreach (var element in elements)
            {
                // If the current element passes the predicate, yield it as a TableElement with the current parentId
                if (predicate(element))
                {
                    yield return element.ToTableElement(parentId);
                    parentId = element.Order;
                }
    
                // Recursively filter children, passing the current parentId to them
                foreach (var child in FilterStructureElements(element.ChildElements, predicate, parentId))
                {
                    yield return child;
                }
            }
        }
    }