How to redirect via .htaccess by replacing part of the address?

Question

1C-Bitrix

There was a section
https://site/catalog/section_1/sub_sec_1/sub_sect_2/
You need to redirect to
https://site/catalog/section-sub_sect_2/

i.e. add section- and add the last section to the address.
I tried it, it doesn't work

RewriteCond %{REQUEST_URI} ^(.*)/catalog/(.*)$ 
   # если строка содержит /dir1/ 
RewriteRule ^(.*)$ %1/catalog/section-%2 [R=301,L] 
   #Перенаправить все URL с начинающиеся с dir1 на dir2 с сохранением дальнейшей структуры URL

I don't know how to add the last section

Answer 1

RewriteRule ^catalog/([^/]+/){3}$ /catalog/section-$1 [R=301,L]