<?xml version="1.0"?>
<man>
	<pers1>
		<f>QQQ</f>
		<i>QQQ</i>
		<o>QQQ</o>
		<dr>QQQ</dr><dr>QQQ</dr>
       </pers1>
	<pers2>
		<f>QQQ</f>
		<i>QQQ</i>
		<o>QQQ</o>
       </pers2>
</man>

    Dim xmlDoc As MSXML2.DOMDocument60
    Dim xmlRoot As MSXML2.IXMLDOMNode
    
    Set xmlDoc = New MSXML2.DOMDocument60
    xmlDoc.async = False
    xmlDoc.validateOnParse = False
    
    If xmlDoc.Load("test.xml") = True Then
        if xmlDoc.???("man/pers1/dr") = True then   '!!! Вот сюда, какую функцию применить?
            Set xmlRoot = xmlDoc.selectSingleNode("man/pers1/dr")
        end if
    end if

Public Sub existsnode()
Dim xDoc As MSXML2.DOMDocument
Dim xmlRoot As MSXML2.IXMLDOMNode
Set xDoc = New MSXML2.DOMDocument
xDoc.validateOnParse = False
xDoc.Load ("test.xml")
Set xmlRoot = xDoc.selectSingleNode("man/pers1/dr")
If xmlRoot Is Nothing Then MsgBox "узел не существует" Else MsgBox "узел существует"
End Sub