I am using this tutorial Giving WordPress Its Own Directory to launch a WordPress (installed in a sub folder called wordpress) by using example.com instead of example.com/wordpress.
It says to copy index.php to your root folder and change the relative path to wp-blog-header.php accordingly. However, my folder structure is a little complex:

To access site root I go to example.com. But to access WordPress I have to go to example.com/wordpress (if anyone wondering why I am using Bitnami WordPress stack AMI and thus everything came pre-configured)
According to tutorial I should copy index.php to site root from WordPress root and change relative location of wp-blog-header.php accordingly.
When index.php was in same directory the function was require('./wp-blog-header.php') . Now this location is to be changed
I have tried all three options I could think of:
../apps/wordpress/htdocs/wp-blog-header.php./wordpress/htdocs/wp-blog-header.phpwordpress/htdocs/wp-blog-header.php
But visiting the domain root gives a server error. Any suggestions?