Make a new line after 3 character after regex

I have following list:

Intel(USA)
Pfizer(USA)6
GeneralElectric(USA)43
Alphabet(Google)(USA)

I can select latest ( in each line by ^.*\K\((?=[^(]*$) regex.
Now I want to make a new line after 3 character after my regex.
for example I get following result:

Intel(USA
)  
Pfizer(USA
)6  
GeneralElectric(USA
)43  
Alphabet(Google)(USA
)  

how to do this by regex and what changes I must apply to my regex?
Note that for some reason I must create a regex for latest ( and can’t use latest ) and note that provide regex for Notepad++

>Solution :

You can match until the last ( and then match optional chars other than ( and )

Then forget what is matched so far, and assert the closing )

In the replacement use a newline.

^.*\([^()\r\n]*\K(?=\))

Regex demo

Or match 3 chars A-Z

^.*\([A-Z]{3}\K(?=\))

Regex demo