VBA for Word - read specific data from MailMerge objects

How about using MailMergeDataSource:

Sub ProcessMailMergeData()
    Dim mmDataSource As MailMergeDataSource
    Dim totalRecords As Long
    Dim currentRecord As Long
    Dim firstName As String
    Dim lastName As String
    Dim department As String
    Dim onVacation As String
    
    ' Ensure the document has an active mail merge data source
    If Not ActiveDocument.MailMerge.DataSource Is Nothing Then
        Set mmDataSource = ActiveDocument.MailMerge.DataSource
        totalRecords = mmDataSource.RecordCount
        
        ' Loop through each record in the data source
        For currentRecord = 1 To totalRecords
            mmDataSource.ActiveRecord = currentRecord
            
            ' Retrieve values from specific fields
            firstName = mmDataSource.DataFields("First name").Value
            lastName = mmDataSource.DataFields("Last name").Value
            onVacation = mmDataSource.DataFields("On vacation").Value
            department = mmDataSource.DataFields("Department").Value
            
            ' Check "On vacation" status and display the relevant info
            If onVacation = "Y" Then
                MsgBox "Name: " & firstName & " " & lastName & vbCrLf & _
                       "Department: " & department, vbInformation, "On Vacation"
            End If
        Next currentRecord
    Else
        MsgBox "No active Mail Merge data source found.", vbExclamation
    End If
End Sub