Syntax for selecting nth element of an array from a filter response

[DonBranson]

I'm trying to formulate a request while using Insomnia, which uses this library. Here's the question I asked over there: Syntax for selecting nth element of an array.

I guess it basically boils down to the problem that the array returned as the result of a filter is not the same as other arrays, so selecting the nth entry is not possible. Since they're using this library, is there anything you could offer to help me formulate requests that get a single entry from a filtered array?