Searching is done in the Nano web application using the searchbox at the top of the page. This search is contextual. A list of possible resource groups will be presented to you as you type in your search terms. These resource groups depend on where you currently are in the web application.
The search results will contain detailed information about each found result and the reason why it satisfies the search terms.
The web application searches within all of your owned Rooms, including all Rooms which are shared to you by other Nano users.
When searching for files, the search is done in the file name and their content as well.