How to change all body copy absolute URLs to relative URLs?

We have a new large dev site, 500+ pages/posts in WordPress.

Unfortunately, our staff added a lot of [dev.domainname.com](https://dev.domainname.com)/about-us URLs instead of /about-us relative URLs.

I tried Better Search and Replace, but that broke all our links so bad that I had to do a site restore.

Any way to make our [dev.domainname.com]) links change to relative links so we can go live with our new site? Thanks.