How to hide product based on user setting

Hi,

I have a function below which excludes WooCommerce products if certain criteria are met.

Currently, in the background, there is a drop-down list of regions/locations which the user have to select by default so products can be excluded by their location.

My question is how do I get the function below to work on non-archived pages ie “search/any page with a custom query that lists products”.

I have also rewritten the function to use pre_get_posts found here https://gist.github.com/anonymous/1af5ca94dcf38634a4c2a8cd41ef5b6a but I seem to be missing something.

If someone could help me out that would be fantastic.

Function tm_remove_product_stock_region($is_visible, $id) {

	$product = wc_get_product($id);

	$product_variable = new WC_Product_Variable($id);
	$product_variations = $product_variable->get_available_variations();

	/** Get users region. */
	$user_region = tm_get_user_region();

	foreach ($product_variations as $variation) {

	   /** Get products regions. */
	  	$product_region = $variation['attributes']['attribute_pa_regions'];

	   //if ( $user_region === $product_region && ! $variation['is_in_stock'] ) {
	   if (!$product->is_in_stock() && $user_region === $product_region) {

	    	$is_visible = false;
			return $is_visible;

	   }

	   //else if ( $user_region === $product_region && $variation['is_in_stock'] ) {
	   else if ($product->is_in_stock() && $user_region === $product_region) {

	    	$is_visible = true;
			return $is_visible;

	   }
	}

}

add_filter('woocommerce_product_is_visible', 'tm_remove_product_stock_region', 10,2);