JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.6.4/js/bootstrap-select.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.6.4/css/bootstrap-select.min.css">
<div class="container">
    <div class="col-lg-6">
        <div class="input-group"> <span class="input-group-addon">Label 1</span>

            <input type="text" class="form-control" name="snpid" placeholder="Test"> <span class="input-group-btn">
    <button class="btn btn-default" type="submit">GO!</button>
  </span>

        </div>
        <!-- /input-group -->
    </div>
    <!-- /.col-lg-6 -->
    <div>
        <BR/>
        <HR>
        <div class="container">
            <form class="form-inline">
                <div class="input-group"> <span class="input-group-addon">Label 2</span>

                    <select id="lunch" class="selectpicker form-control" data-live-search="true" title="Please select a lunch ...">
                        <option>Hot Dog, Fries and a Soda</option>
                        <option>Burger, Shake and a Smile</option>
                        <option>Sugar, Spice and all things nice</option>
                        <option>Baby Back Ribs</option>
                        <option>A really really long option made to illustrate an issue with the live search in an inline form</option>
                    </select>
                </div>
            </form>
            <div>

CSS

.input-group > .input-group-btn:last-child > .selectpicker {
    border-top-right-radius: 5px;
    border-bottom-right-radius: 5px;
}

.input-group > .input-group-btn:first-child > .selectpicker {
    border-top-left-radius: 5px;
    border-bottom-left-radius: 5px;
}