Need help in overriding product-search template in child theme

I was trying to override the product-search.php template in the child theme on my site, but I am unable to do so. Can you please help me with it.

I have done following things till now to do the override

1. Copied the product-search.php file in the relative folder in the child theme
2. Copied the footer.php file in the relative folder in the child theme
3. Tried to add a new relative URL in functions.php as there is a constant defined for Product Search URL in main theme's function.php (it is using include_once() function). But doing this causes 500 error.