You can quickly access your Recent searches, Pinned matters and Recent Matters by using Thread global search function, located on the top of the navigation menu.
In the sample above, Matters is pinned (for easy access to matters first), but you can pin Contacts or Documents if you prefer to view those search results first.
To further assist with your search, you can sort by any of the column headings: Name, Matter Code, Description, etc.
There are page specific search options within most pages on Thread, such as Key dates, Companies, Tasks etc., which only search through the content on those pages.