There is a directory along the way

сайт/catalog/раздел/подраздел/элемент/

(the nesting can be different), the essence of the question, as when changing /catalog/ let's say on /cat/ , save the working links that go like nesting

 /раздел/подраздел/элемент/

THOSE. we start to follow the link

 сайт/catalog/раздел/подраздел/элемент/

and throws us right on

 сайт/cat/раздел/подраздел/элемент/

    1 answer 1

    If catalog is located immediately after the site address, you can do this:

     RewriteEngine On RewriteRule ^catalog/(.+)$ /cat/$1 [L,R=301]

    If the catalog can be anywhere in the path, the rule should be:

     RewriteRule ^(.+/)*catalog/(.+)$ $1cat/$2 [L,R=301]