wordpress php getting search results on same page (changing form action url)

So I’ve got this search filter thing but I want the search results to appear on the same as the filter is on. However it keeps taking me to a separate search page to show the results.

I think I just need to get the form action to be the current url or a certain page url or permalink. <form action="http://localhost/siennahomes_www/property-search-sienna/>

ideally I would like it to be

<form action="http://localhost/siennahomes_www/home-designs/>

I’ve tried putting in an absolute link to test but it appears to be overwritten by a php function. It constantly stays at
no matter how much I try.

The bits of code in the templates are:

Advanced-search:

<?php

global $theme_search_url;

$theme_search_url = get_option('theme_search_url');

global $theme_search_fields;

$theme_search_fields= get_option('theme_search_fields');

if( !empty($theme_search_url) && !empty($theme_search_fields) && is_array($theme_search_fields) ):

    ?>

    <section class="advance-search ">

        <?php

        $home_advance_search_title= get_option('theme_home_advance_search_title');

        if(!empty($home_advance_search_title)){

            ?><h3 class="search-heading"><i class="fa fa-search"></i><?php echo $home_advance_search_title; ?></h3><?php

        }

        get_template_part('template-parts/search-form');

        ?>

    </section>

    <?php

endif;

?>

home-designs page:

<?php

/*

*   Template Name: home designs test

*/

get_header();

/* Theme Home Page Module */

$theme_search_module = get_option('theme_search_module');

?>

    <!-- Content -->

    <div class="container contents">

        <div class="row">

            <div class="span12">

                <!-- Main Content -->

                <div class="main">

                    <?php

                    /* Advance Search Form */

                    get_template_part('template-parts/advance-search-test');

                    ?>

                    <section class="property-items">

                        <div class="search-header">

                            <?php get_template_part('template-parts/sort-controls'); ?>

                        </div>

                        <div class="property-items-container clearfix">

                            <?php

                            /* List of Properties on Homepage */

                            $number_of_properties = intval(get_option('theme_properties_on_search'));

                            if(!$number_of_properties){

                                $number_of_properties = 4;

                            }

                            $search_args = array(

                                'post_type' => 'property',

                                'posts_per_page' => $number_of_properties,

                                'paged' => $paged

                            );

                            // Apply Search Filter

                            $search_args = apply_filters('real_homes_search_parameters',$search_args);

                            $search_args = sort_properties($search_args);

                            $search_query = new WP_Query( $search_args );

                            if ( $search_query->have_posts() ) :

                                $post_count = 0;

                                while ( $search_query->have_posts() ) :

                                    $search_query->the_post();

                                    /* Display Property for Search Page */

                                    get_template_part('template-parts/property-for-home');

                                    $post_count++;

                                    if(0 == ($post_count % 2)){

                                        echo '<div class="clearfix"></div>';

                                    }

                                endwhile;

                                wp_reset_query();

                            else:

                                ?><div class="alert-wrapper"><h4><?php _e('No Properties Found!', 'framework') ?></h4></div><?php

                            endif;

                            ?>

                        </div>

                        <?php theme_pagination( $search_query->max_num_pages); ?>

                    </section>

                </div><!-- End Main Content -->

            </div> <!-- End span12 -->

        </div><!-- End  row -->

    </div><!-- End content -->

<?php get_footer(); ?>

search-form:

<div class="as-form-wrap">
<form class="advance-search-form clearfix" action="<?php global $theme_search_url; echo $theme_search_url; ?>" method="get">
<?php if ( in_array ( 'keyword-search', $theme_search_fields ) ) {
        ?>
<div class="option-bar large">
<label for="keyword-txt"><?php _e('Keyword', 'framework'); ?></label>
<input type="text" name="keyword" id="keyword-txt" value="<?php echo isset ( $_GET['keyword'] ) ? $_GET['keyword'] : ''; ?>" placeholder="<?php _e('Any', 'framework'); ?>" />
        </div>
        <?php
    }

    if ( in_array ( 'property-id', $theme_search_fields ) ) {
        ?>
        <div class="option-bar large">
            <label for="property-id-txt"><?php _e('Property ID', 'framework'); ?></label>
            <input type="text" name="property-id" id="property-id-txt" value="<?php echo isset($_GET['property-id'])?$_GET['property-id']:''; ?>" placeholder="<?php _e('Any', 'framework'); ?>" />
        </div>

I suspect the culprit is this line on the advanced search page:

$theme_search_url = get_option('theme_search_url');