1. Log into your cPanel account.
2. In the Software section, click on the MultiPHP Manager Icon.
3. Scroll down to the end of the page, select your domain from the left side, and see the PHP Version option. With a drop-down list on the right side. Select the appropriate PHP version from the drop-down menu and then click on Apply.

4. Now you want to set PHP 5.6 on Example2, scroll down and select the example2 domain. Then set the PHP version to 5.6.

Congratulations, both of your domains using different PHP versions now.
