Each workspace has it's own file and folder search facility.
To do a quick search of the files/folders in a particular workspace, go to the 'Files' section of that workspace and use its search facility, which is located above the list of files and folders.
As you start to type a search term in the search box it will automatically make suggestions, which can be selected from a drop down menu. This is a purely based on the file or folders name.
As soon as you press return the the search results will be displayed in a list based on relevance. The relevance will also be based on the contents of the file.