.htaccess mod_rewrite permalinks

This maybe a stupide question but my client is pretty firm that they want this doing so I kind of need to find out if its even possible.

Basically I have a page lets call it ‘page1’ and a child of that page ‘page2’ the url to page2 at present is https://www.url.com/page1/page2 with permalinks enabled to be a custom structure – /%category%/%postname%/

What my client is requiring is that page2 sits under page1 in the page navigation but when clicked on navigates to – https://www.url.com/page2 effectively missing out the parent page title in the url. He also only wants this to happen with 1 specific url not on the whole site.

First question is…is this possible? Second question is how!?

I have had a developer friend help me out with some ideas and still no joy, here is the attempt on the .htaccess file:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /beta/

RewriteRule ^url-i-want-to-write\/?$ /actual-path/to-url

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /beta/index.php [L]

</IfModule>
# END WordPress
<IfModule mod_security.c>
<Files async-upload.php>
</Files>
</IfModule>

RewriteRule ^url-i-want-to-write\/?$ /actual-path/to-url

Is the line that was added…

Any help would be greatly appreciated. Thanks.