How to get all values from multiple options

Question 1

$(function(){
    $( "select[name='user_group_join_provisioner[]']" ).each(function(){
        alert($(this).val());    
    });
});

Fillde DEMO

Question 2

try,

HTML:

<body >
<div id="multigroup">
    <fieldset class="fs_group_1" style="width:48%; float:left;margin-right: 3%;">
        <label style="width:96%;">Group <span class="deletegroup rotate">+</span>
        </label>
        <input type="text" value="DBA" class="readonly" readonly style="width:92%;">
        <input type="hidden" name="fk_user_group_id[]" value="16">
    </fieldset>
    <fieldset class="fs_provisioner_1" style="width:48%; float:left;">
        <label>Provisioner</label>
        <select name="user_group_join_provisioner" style="width:92%;">
            <option value="y" selected="selected">Yes</option>
            <option value="n">No</option>
        </select>
    </fieldset>
</div>

<div id="multigroup">
    <fieldset class="fs_group_1" style="width:48%; float:left;margin-right: 3%;">
        <label style="width:96%;">Group <span class="deletegroup rotate">+</span>
        </label>
        <input type="text" value="RESG/GTS/MKT " class="readonly" readonly style="width:92%;">
        <input type="hidden" name="fk_user_group_id[]" value="15">
    </fieldset>
    <fieldset class="fs_provisioner_1" style="width:48%; float:left;">
        <label>Provisioner</label>
        <select name="user_group_join_provisioner" style="width:92%;">
            <option value="y">Yes</option>
            <option value="n" selected="selected">No</option>
        </select>
    </fieldset>
</div>
</body>

JS:

<script>
$(function(){
    $('select[name^="user_group_join_provisioner"]').each(function () {
    alert($(this).val());
});
});
</script>

Question 3

You can get all the values from the select fields with the following code

$(".ajx_disable").each(function(){
        alert($(this).val())})