I have a PHP file at my server root.. index.php .. which include\'s .. DIR/main.php
Now .. DIR/main.php .. has relati
Assuming main.php is a mix of HTML and PHP then when you output a link you'll need to include a prefix:
<a href="<?php echo $web_root; ?>relative/path/">relative link</a>
Where $web_root is your root path ('DIR'). Probably a good idea to define it in a separate include file so you only have to define it once for all your scripts.
The base tag in html works for relative links. See w3schools for an example on how to use it.
The picture isn't too clear but you can probably rearrange a few files and use symlinks to solve the problem.
For your example, you could make a symlink DIR/friend1.php that points to /friend1.php, but you would have to do this for all your files, or just move them.