Configure IDE to open multiple files...

Probably not phpstorm specific but that's what I'm using

Is it possible to configure the IDE to open two files in a horizontal split when one of a pair is selected under certain circumstances?

.e.g

Consider the following dir/file structure

/root
    /actions
        - index.php
    /views
        - index.html

If I open index.html can I get the IDE to automatically open index.php in a horizontal split?