C# XmlNode has ancestor type

Question

I have an XmlDocument in the format below. If I perform the following search

XmlNode title = xmlDoc.SelectNodes("//Book/Title[contains(., \"Title3\")]");

I will get back an XmlNode which is a title. How do I find out if that book falls under publications? I don't always want to assume that title.ParentNode.ParentNode.ParentNode exists. There should be an intuitive way to say:

if(title.hasAncestor("Publication") != null)
{
    // do whatever
}

Any help will be greatly appreciated

<Publications>
    <Novel>
        <Book>
            <Title>Title1</Title>
            <Author>Author1</Author>
            <Year>2000</Year>
        </Book>
        <Book>
            <Title>Title2</Title>
            <Author>Author2</Author>
            <Year>2000</Year>
        </Book>
    </Novel>
    <History>
        <Book>
            <Title>Title3</Title>
            <Author>Author3</Author>
            <Year>2000</Year>
        </Book>
        <Book>
            <Title>Title4</Title>
            <Author>Author4</Author>
            <Year>2000</Year>
        </Book>
    </History>
</Publications>
<StudyGuides>
    <Math>
        <Book>
            <Title>Title5</Title>
            <Author>Author5</Author>
            <Year>2000</Year>
        </Book>
        <Book>
            <Title>Title6</Title>
            <Author>Author6</Author>
            <Year>2000</Year>
        </Book>
    </Math>
    <Science>
        <Book>
            <Title>Title7</Title>
            <Author>Author7</Author>
            <Year>2000</Year>
        </Book>
        <Book>
            <Title>Title8</Title>
            <Author>Author8</Author>
            <Year>2000</Year>
        </Book>
    </Science>
</StudyGuides>

Answer 1

You can do this in XPath by using the ancestor axis:

//Book/Title[contains(., "Title3")][ancestor::Publications]

Answer 2

/Publications/*/Book/Title[contains(., 'Title3')]