I found a similar issue from 2014 marked resolved:
https://bugs.chromium.org/p/chromium/issues/detail?id=132332

I'm using this form to test :
http://jsfiddle.net/9T63L/13/

The best I could do results in :
First : Mark John
Middle : d  (note, no "du", just the letter d)
Last : Pont

Able to reproduce this issue on reported version 61.0.3163.100 and on latest canary 65.0.3285.0 using Windows10 , Mac 10.13.1 and Ubuntu 14.04 with steps mentioned in comment#0. i.e;Autofill doesn't provide the obvious ability to separate first/middle/sur,

This issue is seen from M50[50.0.2166.0]. Hence considering this issue as Non-Regression and marking as Untriaged. 

Could some one from UI>Browser>Autofill team take a look into this issue.

 Issue 792253  has been merged into this issue.

This bug also expresses itself on multi-word last names.

Steps to reproduce the problem:
1. Enter a name with two last-names on a form (e.g. Juan Perez Gonzalez).
2. Choose to save on autofill.
3. Try to autofill the name on another form.
4. The name will be wrongly split into:
  First: Juan
  Middle: Perez
  Last: Gonzalez

What is the expected behavior?
The name will be correctly split into:
  First: Juan
  Last: Perez Gonzalez

What went wrong?
Autofill assumes last-names are single words always, which is not true for people from most Spanish and Portuguese speaking countries, and I assume other cultures I'm not familiar with.

The worst part is the autofill settings won't let me individually edit it so that it's filled correctly in the future.

There's only a "name" field, which will again parse the name incorrectly, if it could be divided into first/middle/last I could *at least* manually fix the issue (but a lot of people won't dive into the menus to fix this).

I have this issue as well:

Correct:
First: Andrew
No middle name
Last: de los Reyes

What Chrome does:

First: Andrew de
Middle: los
Last: Reyes

I specifically went in to fix this and it seems impossible!

I can repro, I'll mark this as available and someone from the team will take it.

Thanks for the report!

I should add that having the first letter be lowercase to repro is not a
requirement. This also affects people like me with two last names, both of
which are capitalized.

Luis

If Chrome stored the name split by components (first, middle, last) at least it would be possible to edit the stored entry in chrome://settings/autofill and work around any broken heuristic in name detection. This would also help with bug 89111.
Last names with many words are awfully common in some parts of the world, and Chrome autofill becomes a pain to use. Even if you enter your name correctly in a form, when you use autofill for any other fields, it overrides your name.

Spliting the components is actually an okr for this quarter.