リストとサブリストの関係が必要な場合は、以下のコード ブロックを試すことができます。
static void Main(string[] args)
    {
        try
        {
            Application app = new Application();
            Document doc = app.Documents.Add();
            Range range = doc.Range(0, 0);
            range.ListFormat.ApplyNumberDefault();
            range.Text = "Birinci";
            range.InsertParagraphAfter();
            ListTemplate listTemplate = range.ListFormat.ListTemplate;
            //range.InsertAfter("Birinci");
            //range.InsertParagraphAfter();
            //range.InsertAfter("İkinci");
            //range.InsertParagraphAfter();
            //range.InsertAfter("Üçüncü");
            //range.InsertParagraphAfter();
            Range subRange = doc.Range(range.StoryLength - 1);
            subRange.ListFormat.ApplyBulletDefault();
            subRange.ListFormat.ListIndent();
            subRange.Text = "Alt Birinci";
            subRange.InsertParagraphAfter();
            ListTemplate sublistTemplate = subRange.ListFormat.ListTemplate;
            Range subRange2 = doc.Range(subRange.StoryLength - 1);
            subRange2.ListFormat.ApplyListTemplate(sublistTemplate);
            subRange2.ListFormat.ListIndent();
            subRange2.Text = "Alt İkinci";
            subRange2.InsertParagraphAfter();
            Range range2 = doc.Range(range.StoryLength - 1);
            range2.ListFormat.ApplyListTemplateWithLevel(listTemplate,true);
            WdContinue isContinue =  range2.ListFormat.CanContinuePreviousList(listTemplate);
            range2.Text = "İkinci";
            range2.InsertParagraphAfter();
            Range range3 = doc.Range(range2.StoryLength - 1);
            range3.ListFormat.ApplyListTemplate(listTemplate);
            range3.Text = "Üçüncü";
            range3.InsertParagraphAfter();
            string path = Environment.CurrentDirectory;
            int totalExistDocx = Directory.GetFiles(path, "test*.docx").Count();
            path = Path.Combine(path, string.Format("test{0}.docx", totalExistDocx + 1));
            app.ActiveDocument.SaveAs2(path, WdSaveFormat.wdFormatXMLDocument);
            doc.Close();
            Process.Start(path);
        }
        catch (Exception exception)
        {
            throw;
        }
    }
この点に注意してください: 入力の長さがわからない場合は、次のように範囲の値の終了を定義してはなりません。
static void Main(string[] args)
    {
        try
        {
            Application app = new Application();
            Document doc = app.Documents.Add();
            Range range = doc.Range(0, 0);
            range.ListFormat.ApplyNumberDefault();
            range.Text = "Birinci";
            range.InsertParagraphAfter();
            ListTemplate listTemplate = range.ListFormat.ListTemplate;
            //range.InsertAfter("Birinci");
            //range.InsertParagraphAfter();
            //range.InsertAfter("İkinci");
            //range.InsertParagraphAfter();
            //range.InsertAfter("Üçüncü");
            //range.InsertParagraphAfter();
            Range subRange = doc.Range(range.StoryLength - 1, range.StoryLength - 1);
            subRange.ListFormat.ApplyBulletDefault();
            subRange.ListFormat.ListIndent();
            subRange.Text = "Alt Birinci";
            subRange.InsertParagraphAfter();
            ListTemplate sublistTemplate = subRange.ListFormat.ListTemplate;
            Range subRange2 = doc.Range(subRange.StoryLength - 1, range.StoryLength - 1);
            subRange2.ListFormat.ApplyListTemplate(sublistTemplate);
            subRange2.ListFormat.ListIndent();
            subRange2.Text = "Alt İkinci";
            subRange2.InsertParagraphAfter();
            Range range2 = doc.Range(range.StoryLength - 1, range.StoryLength - 1);
            range2.ListFormat.ApplyListTemplateWithLevel(listTemplate,true);
            WdContinue isContinue =  range2.ListFormat.CanContinuePreviousList(listTemplate);
            range2.Text = "İkinci";
            range2.InsertParagraphAfter();
            Range range3 = doc.Range(range2.StoryLength - 1, range.StoryLength - 1);
            range3.ListFormat.ApplyListTemplate(listTemplate);
            range3.Text = "Üçüncü";
            range3.InsertParagraphAfter();
            string path = Environment.CurrentDirectory;
            int totalExistDocx = Directory.GetFiles(path, "test*.docx").Count();
            path = Path.Combine(path, string.Format("test{0}.docx", totalExistDocx + 1));
            app.ActiveDocument.SaveAs2(path, WdSaveFormat.wdFormatXMLDocument);
            doc.Close();
            Process.Start(path);
        }
        catch (Exception exception)
        {
            throw;
        }
    }