How to get current directory in apache virtualhost

I am looking for a way to do conditional actions based on the current directory.

I will refer to this as $DIRNAME in two examples to try and explain use cases.

# Prepend a file if it is a wordpress site.

<Directory ~ /home/user/sites/*>
    <If "-f '/home/user/sites/' . $DIRNAME . '/wp-config.php'">
        php_admin_value auto_prepend_file /home/user/sites/$DIRNAME/wp-preload.php
    </If>
</Directory>


# Add a custom Alias if a file exists.

<Directory ~ /home/user/sites/*>
    <If "-f '/home/user/sites/' . $DIRNAME . '/admin'">
        Alias /admin /home/user/sites/$DIRNAME/admin/public
    </If>
</Directory>