Enter a keyword or an expression in the search field above your newsfeed or a group home page. You can also use advanced search options to narrow your search (by label, author ...). To search in file contents you have to filter your newsfeed by Files.

You can also search for chat messages from a chat conversation : you can type in keywords in the Search field at the top of the conversation. You can also expand your search by searching in all conversations. By clicking on the paper clip icon it's possible to search for files only.

You can search for users from the users directory. You can also use advanced search options to narrow your search (by location, skill ...).