JSFiddle - React, Tailwind, and code Playground

HTML

<select id="id_user" name="user" multiple="multiple">
    <option value="1">User 1</option>
    <option value="2">User 2</option>
    <option value="3">User 3</option>
    <option value="4">User 4</option>
</select>

<div id="selectControls"></div>

JavaScript

$(function() {
    $('#id_user > option').each(function() {
        var $this = $(this);
        $('#selectControls').append($('<span></span>')
            .text("Select " + $this.val() + " user")
            .click(function() { $this.attr('selected', true); $('#id_user').focus(); })
        ).append('&nbsp;').append($('<span></span>')
            .text("Deselect " + $this.val() + " user")
            .click(function() { $this.removeAttr('selected'); $('#id_user').focus(); })
        ).append('<br />');
    });
});