Search and Replace on individual folders only

I work at a college. We have multiple departments. Currently we are having a high turn over. For example, our HR department(30 pages), I have had to replace names and email with the new employees.
It is unbelievable to me that you can not search and replace on just a department and not the whole site. It is so cumbersome to go one page at a time replacing. Sometime the name and email are on a page more than once. It takes forever.
I have already taken a lot of time replacing.
Also our college renames departments every so often.
I was told to never search and replace on the whole site.

The page I need help with: [log in to see the link]