You can search a Contact or Company by phone number, email or on any other contact field.
The global search functionality – which was previously in the left pane menu – is now accessible from a “Search” link at the bottom of the main screen of Contacts app on your mobile.
Enter a string of characters or a phone number to search on all Contacts or Companies.
Upvise Blog 
These very rare updates would be much more helpful with some screenshots.
Hi David, great idea, we have added a screenshot of the Contacts home page.