Open Links in Dashboard Portlet in Top Window

In the Dashboard Menu, go to Custom Header and add the following code.

<script type="text/javascript">
$(function(){
    //iterate thru iframe elements
    //$("iframe").each(function(){
    //wait for iframe to load is a better idea
    $('iframe').on('load', function(){
        $(this).contents().find("a").attr("target", "_top");
    });
});
</script>

Every link found in the portlet will now open in the parent frame. You may adjust the code accordingly to suit your needs.