RCP_Levels::get_level_field PHP Method

    public function get_level_field($level_id = 0, $field = '')
    {
        global $wpdb;
        $value = wp_cache_get('level_' . $level_id . '_' . $field, 'rcp');
        if (false === $value) {
            $value = $wpdb->get_col($wpdb->prepare("SELECT {$field} FROM {$this->db_name} WHERE id='%d';", $level_id));
            wp_cache_set('level_' . $level_id . '_' . $field, $value, 'rcp', 3600);
        }
        $value = $value ? $value[0] : false;
        return apply_filters('rcp_get_level_field', $value, $level_id, $field);
    }

function rcp_get_subscription_access_level($id)
{
    $levels = new RCP_Levels();
    $level = $levels->get_level_field($id, 'level');
    if ($level) {
        return $level;
    }
    return false;
}