? That code's meaning is extremely clear: it reads from a list of URLs that return JSON lists of JSON objects. For each URL, it pulls out some property and checks whether each line does not contain the string 'filter'. Those lines which clear the 'filter'-filter are written to a file whose name is the line of the original input file which contained the URL pinged suffixed by the extension '.data'.

It's very easy to read and modify if you just write it out longwise, which is what I'd always do in some actual script. (I also like to put reading data at the beginning of the pipeline, so I'd use a useless use of cat here.) To illustrate:

  N=0
  cat links.txt \
    | while read -r URL; do
        curl "$URL" \
          | jq '.data[].someProp' \
          | grep -v "filter" \
          > "$N.data"
        N="$((N+1))"
      done

It's a very simple pipeline with a single loop. It's not very different from pipelines you might write to transform some data using a thread macro in Clojure, or method chaining against a collection or stream in OOP languages like Java or Scala or Ruby or whatever you like.