Different menus without categories

I found the following code on this stackexchange from this page Display a portion/ branch of the menu tree using wp_nav_menu(). It almost does what I need, except I need the whole menu, the item was chosen from, instead of the item name. I also need only 1 menu to show at a time. I basically would like to get different menus on each page, without using categories, based off the menu item chosen at that point. I really think this might work but because of my lack of skills I’ve just not been able to rewrite it so that it works how I need.

This is the code.

<?php

add_filter( 'wp_nav_menu_objects', 'submenu_limit', 10, 2 );

function submenu_limit( $items, $args ) {

    if ( empty($args->submenu) )
        return $items;

    $parent_id = array_pop( wp_filter_object_list( $items, array( 'title' => $args->submenu ), 'and', 'ID' ) );
    $children  = submenu_get_children_ids( $parent_id, $items );

    foreach ( $items as $key => $item ) {

        if ( ! in_array( $item->ID, $children ) )
            unset($items[$key]);
    }

    return $items;
}

function submenu_get_children_ids( $id, $items ) {

    $ids = wp_filter_object_list( $items, array( 'menu_item_parent' => $id ), 'and', 'ID' );

    foreach ( $ids as $id ) {

        $ids = array_merge( $ids, submenu_get_children_ids( $id, $items ) );
    }

    return $ids;
}
?>

<?php

class Selective_Walker extends Walker_Nav_Menu
{
    function walk( $elements, $max_depth) {

        $args = array_slice(func_get_args(), 2)
        $output = '';

        if ($max_depth < -1) //invalid parameter
            return $output;

        if (empty($elements)) //nothing to walk
            return $output;

        $id_field = $this->db_fields['id'];
        $parent_field = $this->db_fields['parent'];

        // flat display
        if ( -1 == $max_depth ) {
            $empty_array = array();
            foreach ( $elements as $e )
                $this->display_element( $e, $empty_array, 1, 0, $args, $output );
            return $output;
        }

        /*
         * need to display in hierarchical order
         * separate elements into two buckets: top level and children elements
         * children_elements is two dimensional array, eg.
         * children_elements[10][] contains all sub-elements whose parent is 10.
         */
        $top_level_elements = array();
        $children_elements  = array();
        foreach ( $elements as $e) {
            if ( 0 == $e->$parent_field )
                $top_level_elements[] = $e;
            else
                $children_elements[ $e->$parent_field ][] = $e;
        }

        /*
         * when none of the elements is top level
         * assume the first one must be root of the sub elements
         */
        if ( empty($top_level_elements) ) {

            $first = array_slice( $elements, 0, 1 );
            $root = $first[0];

            $top_level_elements = array();
            $children_elements  = array();
            foreach ( $elements as $e) {
                if ( $root->$parent_field == $e->$parent_field )
                    $top_level_elements[] = $e;
                else
                    $children_elements[ $e->$parent_field ][] = $e;
            }
        }

        $current_element_markers = array( 'current-menu-item', 'current-menu-parent', 'current-menu-ancestor' );  //added by continent7
        foreach ( $top_level_elements as $e ){  //changed by continent7
            // descend only on current tree
            $descend_test = array_intersect( $current_element_markers, $e->classes );
            if ( !empty( $descend_test ) ) //unset ($children_elements);
                $this->display_element( $e, $children_elements,2,0, $args, $output );
               //$this->display_element( $e, $children_elements,$max_depth,0, $args, $output );
        }

        /*
         * if we are displaying all levels, and remaining children_elements is not empty,
         * then we got orphans, which should be displayed regardless
         */
         /* removed by continent7
        if ( ( $max_depth == 0 ) && count( $children_elements ) > 0 ) {
            $empty_array = array();
            foreach ( $children_elements as $orphans )
                foreach( $orphans as $op )
                    $this->display_element( $op, $empty_array, 1, 0, $args, $output );
         }
        */
         return $output;
    }
}
?>

<?php wp_nav_menu(
   array(
       //'theme_location'=>'business',
        'menu'=>'business',
       'walker'=>new Selective_Walker() )
   ); ?>

 <?php wp_nav_menu(
   array(
       'theme_location'=>'personal',
       'walker'=>new Selective_Walker() )
   ); ?>

The link to where I have also posted for help is below, no one has answered there either and I am not sure if I posted it wrong or something, and I am not sure if I am breaking any forum rules. I only mention it because I want to come clean that I know I posted it in 2 places. Please help, please share with your colleagues if you don’t know.