Step 1- Go to uploaded documents in an activity
Image: Document cards inside an activity
Step 2 - Click to view the document
Image: Document view with the comments panel
Step 3 - Add a comment and tag your teammate if needed
Step 4 - Getting notified about tags on documents
If someone tags you in a document, you will get a Todo on your dashboard, here you can keep a track of all the documents you were given feedback on. You can simply click on the Todo to visit the document you were tagged in.