In regards to
Assuming that you already have CageFS, PHP Selector and mod_lsapi installed, perform the following steps:
1. Setup mod_lsapi (no matter globally or per domain).
2. Create /etc/container/php.handler file with handlers for different versions:
application/x-lsphp52 /opt/alt/php52/usr/bin/lsphp application/x-lsphp53 /opt/alt/php53/usr/bin/lsphp application/x-lsphp54 /opt/alt/php54/usr/bin/lsphp application/x-lsphp55 /opt/alt/php55/usr/bin/lsphp
3. Restart Apache.
4. Create .htaccess file in desired directory where you want to have a different from default PHP version with right handler:
AddType application/x-lsphp53 .php5 .php4 .php .php3 .php2 .phtml
As the result, subdirectories will use the same PHP version as parent unless you overwrite it with another .htaccess entry in that subdirectory.
To match PHP extensions selection with extensions selected by end user for that PHP version in PHP Selector you have to follow http://docs.cloudlinux.com/index.html?php_extensions.html.