Tagbox
Select2 tag box Third-party libraries: Select2 MIT
Survey.Survey.cssType = "bootstrap";
Survey.defaultBootstrapCss.navigationButton = "btn btn-green";

var json = {
  "elements": [
    {
      "type": "tagbox",
      "isRequired": true,
      "choicesByUrl": {
        "url": "https://restcountries.eu/rest/v1/all"
      },
      "name": "countries",
      "title": "Please select all countries you have been for the last 3 years."
    }
  ]
};

window.survey = new Survey.Model(json);


survey.onComplete.add(function(result) {
    document.querySelector('#surveyResult').innerHTML = "result: " + JSON.stringify(result.data);
});

survey.data = { countries: ['Andorra'] };

ReactDOM.render(<Survey.Survey model={survey}  />, document.getElementById("surveyElement"));

<!DOCTYPE html>
<html>
<head>
    <title>Select2 tag box for plaform Reactjs, SurveyJS Library Example</title>
    <script src="https://unpkg.com/jquery"></script>
    <script src="https://unpkg.com/react@15/dist/react.js"></script>
    <script src="https://unpkg.com/react-dom@15/dist/react-dom.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.23/browser.js"></script>
<script src="/bundles/prettydiff?v=E3KTA7j8SjgR8NaAhm1jADBJxbWj5Yx1GQ2EdHBzuxE1"></script>

    <script src="https://surveyjs.azureedge.net/0.98.1/survey.react.js"></script>
  
    <link rel="stylesheet" href="https://unpkg.com/bootstrap@3.3.7/dist/css/bootstrap.min.css">
    <link rel="stylesheet" href="./index.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.4/js/select2.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.4/css/select2.min.css" rel="stylesheet" />
    <script src="https://unpkg.com/surveyjs-widgets"></script>

</head>
<body>
                <div id="surveyElement">
            </div>
    <div id="surveyResult"></div>

<script type="text/babel" src="./index.js"></script>

</body>
</html>
.btn-green {
  background-color: #1ab394;
  color: #fff;
  border-radius: 3px;
}
.btn-green:hover, .btn-green:focus {
    background-color: #18a689;
    color: #fff;
}
.panel-footer {
    padding: 0 15px;
    border:none;
    text-align: right;
    background-color: #fff;
}