How to determine which registered sidebar area a custom widget is loaded into

The information you want is in the $args parameter.

var_dump($args); // inside your widget method

Look at the ‘name’ and ‘id’ array elements.

Your code should look something like:

function widget( $args, $instance ) {
    extract($args);
    $title = apply_filters( 'widget_title', empty($instance['title']) ? '' : $instance['title'], $instance );
    $text = apply_filters( 'widget_text', $instance['text'], $instance );
    $hide_title = isset( $instance['hide_title'] ) ? $instance['hide_title'] : false;
    $filter = isset( $instance['filter'] ) ? $instance['filter'] : false;
    if ('home-footer-widget' != $args['id'] && 'footer-two' != $args['id']) echo $before_widget;
    if ( $title && !$hide_title )echo $before_title . $title . $after_title;
    if ( $text ) echo $filter ? wpautop($text) : $text;
    if ('home-footer-widget' != $args['id'] && 'footer-two' != $args['id']) echo $after_widget;
}