Use the [URLParam param='paramName'] shortcode to display GET parameters from the current URL

URL-Param-Shortcode.php

<?php // ignore this line - only for formatting

// Use the [URLParam param='paramName'] shortcode to display GET parameters from the current URL

function displayURLparam( $atts ) {
    extract( shortcode_atts( array(
        'param' => 'param',
    ), $atts ) );
    return esc_attr(esc_html($_GET[$param]));
}
add_shortcode('URLParam', 'displayURLparam');