Oh-hohohoho, splitting of chapters! It can either save a chapter, or you lose vital information.
But of course, it depends on what you mean by "splitting a chapter". Are you talking about splitting it into two chapters at a single spot, or keep it as one chapter, but transitioning to a different location?
Let's start with the first half of the question, splitting it into two chapters.
I had to make that decision a good few times with my own story, and for the most part, I split the chapter in two, which did work to its advantage. It takes the right timing and judgment to know where to make that split.
A personal, more recent example: chapter nineteen. It actually would've been much longer than it already is. It is the beginning of the climax, and the climax, as we all know, is the best part of a story. That is when the issues all come together into a final battle to determine the fate of the future. The first half of chapter nineteen is more of an emotional moment to give us that feeling this may be the last time all of these characters will be together (mainly the two main characters). The last half, while emotional in itself, marks the beginning of the climax. Well, while writing it, I got stuck. The reason was because I was writing way too much at once. And because I hate to keep my readers waiting, I went ahead to cut the chapter where needed, and move on from there.
Of course, this bumps up my expected number of chapters from twenty to twenty-one, not that there's anything bad about it, I just pushed myself a little further about it.
So that decision helped me move along, even though I
am still struggling with this chapter (as you can probably see). And it was for the best, I have this unshakable feeling chapter twenty is going to be
extremely big, I'm technically, like, 15% done (probably, I'm not good at math), and I'm at thirty-odd pages already. My longest chapter is almost 50 pages, but this one is going to be twice as long, if not more. So in a way, I'm very grateful I made that split so that way I can have one chapter dedicated to the climax all to itself.
Now back to you.
My plan for chapter five is to split it into two parts, Each part will tell the same sequence of events from the perspective of different Pokemon, and two humans. Each split part of the chapter tells the same thing, but they are slightly different because each perspective notices more, or less, or different things entirely.
Hmm... should you do that? Would your readers want to read two chapters with virtually the same information? This is going to be in two different perspectives, one in a Pokémon's perspective, and the other with the humans. Were they together at all during this? This is the most important question when it comes to this issue. If the two different species were together in most of the story, or at least in some parts, then this is where the writing is going to get difficult. Yes, you're writing two very different thoughts and emotions, but the concept is going to be the same.
This is where the second question comes in: transitioning to a different location.
In chapter twenty, the entire setting takes place in one location (or landmark if you want to get technical), but in different levels with different characters each time. It's similar to an earlier chapter I did where there were different characters in different locations tackling different issues. If this is what you're doing with this chapter, then detail on their thoughts, emotions, and actions is crucial. I know nothing about your story, whether it's in third-person, or in first-person view, but either way, you need to be extremely careful how you write this chapter.
There's nothing wrong with doing this, every story does it at some point or another. It's just how you
handle it. You need to have a good perspective of your story, and by "good perspective", I mean rounding it into some form of three-dimensional world. Showing two different sides of the issue works in that field. However, you really cannot have a rewrite of a similar scene right beside it
without a good reason. I can't speak for others like I can speak for myself, but the chances are very high your readers will think you posted the same information twice in the same post, and may got confused, or frustrated at the feeling of been gypped. So this is where cautious editing takes place.
As I tend to go everywhere at once when it comes to an interesting topic and lose my train of thoughts (and when I'm running out of time), does this all make sense to you? Did I answer your question? I hope I did. If not, don't be afraid to be confused and ask more questions. I'm sure I missed some information somewhere.
Otherwise, happy writing!