Linq to Xml：在选择父节点时突出显示相应的子节点

I'm working on a LINQ to XML query where if I select the branch(parent node), only child nodes which is specific to that branch should highlight. I am developing an ASP.NET tool, in that I need to read an XML file, which reads parent node first, based on user selection, it will read child nodes, now the problem is if I select the parent node, it is reading all the child nodes from all parent node, so I need a query in which it should read respective child node upon selecting the branchI'm working on a LINQ to XML query where if I s