When creating some experiments in Nelio A/B Testing, you need to indicate which is the original page/post you want to put under test. To do so, you have a selection list where you can see some of your pages/posts:

As you can see, the list only show a partial selection of your posts and pages. However, there is the chance to find the specific post and page that you want to test by writing it's title (or some keywords) into the text field that is located over the list of entries (marked with the icon of a magnifying glass in the right side). When writing some words, the results in the list will dynamically change showing the entries that are relevant, and underlining the words that match to the written keywords: