You can use Google search (advance search)
example
"this exact word or phrase" all these words (no " ") or combination
when I want to search only a specific forum I use the part of the url after posts/xxxxxxxxxxxx/ in quotes plus any word(s)
then space site:
medhelp.org note medhelp auto hotlinks in the forum don't click the links here.
if you want to check this example, copy the entire line below and paste into Google search. Checkout the results.
"Improve-MedHelp-Suggestions" search site:
medhelp.org
Select search tools to limit dates or custom date range.
experiment using member name or other search words.