This function is for developers, which use Oxygen and still want to override plugin-files when it reads in their documentation such as

1. Create a folder in your theme folder called search-filter.
2. Copy the file wp-content\plugins\search-filter\templates\results.php from the templates folder in to the newly created folder in your theme – wp-content\themes\your-theme-name\search-filter\results.php

Where to put such files, if Oxygen is not a theme and won't uses themes ?