https://learn.microsoft.com/ja-jp/dotnet/api/system.xml.xpath.xdocumentextensions.toxpathnavigable?view=netframework-4.8.1&viewFallbackFrom=net-10.0
XDocumentExtensions.ToXPathNavigable(XNode) Method (System.Xml.XPath) | Microsoft Learn
Returns an accessor that allows you to navigate and edit the specified XNode.
xnodemethodsystemxmlxpath