Yeah, Trip's right about SMF. Best you can do here is use search with a narrowed date range by suggesting the search between x days using the boxes at the bottom of search... or you could use Google and try a search for site:carls-sims-4-guide.com/forum/ and "put in quotes" the thread's exact title. This would probably be the best way. Google has the whole forum indexed, so if you search the exact title of the thread you are in you might have some luck. The site: part will restrict it to this area of the website.
Hope this helps!