I was listening to the theme from "Game of Thrones" and noticed this section (listen for the drum). There is a hemiola that takes four beats, but the song fits 3/4 best. That would make the hemiola cross measures, and the best way of notating it that I can think of is a triplet of half notes. How is this typically notated? If there is a better way if notating the hemiola, I'd appropriate it if you would include that in your answer, but also include how to notate multi-measure triplets.
Bob Broadley's answer shows the best that most (commercial) notation programs can do without "faking" the output, but in complicated situations this style of notation can be easier to read:
The notes in the tuplets are spaced relative to the other notes in the score as if the bar-lines did not exist.
(Note, the image was requested by the OP to explain my comment - I also couldn't hear what the first part of the question is asking about)
If this sort of cross-rhythm is a fundamental part of the structure of the music, you might want to write different time signatures on different staves of the score, like
I haven't listened to the music you link to; besides, it sounds from the comments like the rhythm may not in fact be in triplets.
However, if you do want to notate triplets across a barline, you can just use a different triplet value and tie across the barline. Both the examples below give the same rhythm: nine consecutive crotchet triplets. However, the 3/4 example requires using quaver triplets and ties.