the only advanced search thing you're missing that works for this-thread search is restricting it to newer than/older than date range, but if you really want it, you can make separate quick and advanced searches with the settings you want, copy-paste the missing parameters from one url into the other (either thread id one or the newer/older ones), change the search id to a random value, and execute that in the address bar.
if you note down the parameters somewhere, next time you can skip straight to putting a search url together from them.
i tried that with relevance to date and it didnt work. Not sure what i messed up, do you have an example url for advance search within a single thread? Thanks for reply
once searched for, the result is cached and the search id it got assigned has to be changed to something else to perform a new search (e.g. if you wanted to replace "within" in the url with another keyword).