bootstrapSelect title
HTML
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.12.4/css/bootstrap-select.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/popper.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.12.4/js/bootstrap-select.js"></script>
<select id="mySelect" class="selectpicker form-control">
<option data-hidden="true" value="" disable>Please select a type of fruit…</option>
<option title="a" value="apple">Apple</option>
<option title="b" value="pear">Pear</option>
<option title="c" value="banana">Banana</option>
<option title="d" value="orange">Orange</option>
</select>
CSS
/* bootstrap-select issue with bootstrap 4!
https://github.com/silviomoreto/bootstrap-select/issues/1135 */
.bootstrap-select.show>.dropdown-menu>.dropdown-menu {
display: block;
}
.bootstrap-select > .dropdown-menu > .dropdown-menu li.hidden{
display:none;
}
.bootstrap-select > .dropdown-menu > .dropdown-menu li a{
display: block;
width: 100%;
padding: 3px 1.5rem;
clear: both;
font-weight: 400;
color: #292b2c;
text-align: inherit;
white-space: nowrap;
background: 0 0;
border: 0;
}