How to find old questions/threads on Apple Community forums?

For threads you started or are subscribed to, look in your subscriptions page.

dunnyt00ns’s Subscriptions - Apple Community

The subscriptions list is limited to around 3 months or so of back threads.

For anything older, you would need to use a search engine. The forum search doesn't really work for that unfortunately. Google may work better. You enter your user name in the forums and something you said in the thread you are looking for or the actual title if you know it and follow it with "site:discussions.apple.com"

With Google or DuckDuckGo search:

site:discussions.apple.com your search words here

or:

site:discussions.apple.com “dunnyt00ns” your search words

You can also use the site-local search, selecting search, and then restricting to a specific nickname:

then restrict the search to a particular author:

For items in the last few months, there are some showing on your profile page.

Access by clicking on your name, then View Profile, then Subscriptions

That does not work well for MrHoffman, or for me, because that list is very long.

Grant Bennet-Alder wrote:

For items in the last few months, there are some showing on your profile page.

Access by clicking on your name, then subscriptions

Unfortunately, the ASC subscriptions mechanism has two disparate and conflicting purposes.

Following a busy community or a busy nickname will bury the ability to find your own postings.