Let's say you have a subdomain of a subdomain, such as sub.sub.domain.tld, how do you remove sub.sub.domain.tld from Google while keeping sub.domain.tld in the Google search results. The answer is to verify the sub.sub.domain.tld property directly in Search Console and remove just that property.
This question came up on Reddit where the user asked, "I have a domain property GSC for my main site (which is a subdomain itself) and I want to use the removals tool to remove a number of sub-subdomains from search results. From what I have read online, it looks like I should be able to use the prefix option and that will just remove the sub-subdomain and leave the primary subdomain alone , but wanted to see if anyone had experience doing this."
John Mueller from Google joked, "Hey, I have practice with this, lol." I wonder if he is referring to his site disappearing from Google Search a couple of weeks back.
His advice was to verify the sub sub domain in Google Search Console and use the removal tool there to remove that subdomain of the subdomain. If it doesn't work and everything vanishes, you can undo it pretty quickly, so it wouldn't be too devastating...
Here is what John wrote:
What you'd need to do is verify the subdomain as a separate site, and then use the URL removal feature in search console to have the whole subdomain removed. The other subdomains - including higher level ones - should be unaffected. The only exception I'm aware of is that "www" subdomains take out the non-www versions too (don't use the tool for canonicalization, it won't work for that - it should also be clear in the documentation).In the worst case (if you get it totally wrong), the removal will take effect within a few hours, you can click "cancel" if you got it wrong, and it'll be back in a few hours. ("few hours" might be up to a day, I always found it to be much faster). Try it out on something that you don't particularly care about, it's not as scary as it sounds & easy to revert.
You can access the removal tool in Google Search Console over here:
Forum discussion at Reddit.