If a document has been shared with you, it is easy to find it on the Microsoft Office Home page (office.com).  

 Go to www.office.com in your preferred web browser and sign in using your NU email address and password.  

At the top of the page, you will see Recommended documents; scroll down to the Quick access area.  

Options are: All | Recently opened | Shared | Favorites.  Click on the Shared option.  

Files are listed by when they were last accessed.  

To search for a specific shared document, use the CTRL + F option and add the name, either of the person who shared the document or the name of the document. Search terms will be highlighted on the page. 

Note: The Search box at the top of the page will show results that include content across SharePoint, Teams, and OneDrive.  

Resource:  
See Files Others Have Shared with You (Microsoft)