Htaccess - Rewrite Only Inside Folder

I hava a folder - careers - and i want to do the rewrite only for the files of that folder, for example: mydomain.com/file.html -> its out of the folder mydomain.com/folerone/fi

Solution 1:

put the .htaccess file inside the careers folder

RewriteRule item([0-9]*)?$ index.php?itemid=item$1 [QSA]