I know how to use the general search, but it simply takes me to a google search results page that runs the search as:
"search phrase" site:https://forum.arduino.cc
Which searches the entire forum.
How do I search only in the IoT Cloud Beta forum?
Unfortunately, we don't have a local search functionality in this forum so there is no way to perfectly limit a search to one forum board. The best you can do is to add the keywords of the forum board name to your search: "Products" "Create" "IoT Cloud Beta". You may get some results that are from other boards and just happen to have those keywords in their text, but since in this case the keywords are fairly specific I think that won't be so much of a problem.