如果你希望规则只在域为"tz433.tld"时执行，你需要这个条件:

RewriteCond %{HTTP_HOST} ^(www\.)?tz433\.tld

并将 "jobs/" 和 "jobs" 重定向到 "tz433.tld/about-us/jobs.html"，您可以尝试以下方法之一:

RewriteRule ^jobs/?/about-us/jobs.html [R=301,L]# 或者重写规则 ^jobs/?http://tz433.tld/about-us/jobs.html [R=301,L]

I would like to have an alias and redirect the URL tz433.tld/jobs/ to the page tz433.tld/about-us/jobs/.

This is what I've tried by far; it didn't work:

RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\.tz433\.tld/jobs/$
RewriteRule (.*) http://tz433.tld/about-us/jobs.html [R=301,L]

The problem is, in this root path there are multiple domains, because it is a multisite typo3 installation. So something like "redirect /jobs to /about-us/jobs" isn't working because it should only happen for a specific domain (tz433).

The next specific thing is www.tz433.tld automatically redirects to tz433.tld. So it should also work with www.tz433.tld/jobs/ and tz433.tld/jobs. Both should redirect to tz433.tld/about-us/jobs.html.

How can I achieve that successfully?

If you want the rule to only execute when the domain is "tz433.tld", you need this condition:

RewriteCond %{HTTP_HOST} ^(www\.)?tz433\.tld

And to redirect "jobs/" and "jobs" to "tz433.tld/about-us/jobs.html", you can try one of these:

RewriteRule ^jobs/? /about-us/jobs.html [R=301,L]
# or
RewriteRule ^jobs/? http://tz433.tld/about-us/jobs.html [R=301,L]