You can search for task titles, assigned users, checklist items and much more, directly from your dashboard or from within a project.
To do this, click on the search button in the right corner of the top bar, and put a keyword in the search bar. Alternatively, you can click ⌘Ctrl+Shift+K
You can easily filter and search by project, assignee, due date and tags.
If you're looking for the old Smart Search just press ⌘Ctrl+K.