This example covers the following functions:

• ARRAYSLICE - Returns an array that is a slice of another array, based on the provided starting and ending index numbers. See ARRAYSLICE Function.
• ARRAYMERGEELEMENTS - Merges the elements of an array together into a string. See ARRAYMERGEELEMENTS Function.

Source:

The following set of arrays contain results, in order, of a series of races. From this list, the goal is to extract a list of the podium finishers for each race as a single string.

Transformation:

From the list of arrays, the first step is to gather the top-3 finishers from each race:

The above captures the first three values of the RaceResults arrays into a new set of arrays. 

The next step is to merge this new set of arrays into a single string:

Results: