What does it mean to thread a comment?
The term “comment threading” refers to grouping all responses to a specific comment together underneath it - this creates a separate conversation view which is also known as a “thread”. Comment threading is a feature found in the comments of Channel posts and articles.
Why can't I see threaded comments in Excel?
To show all the threaded comments on the active sheet, follow these steps: On the Excel Ribbon, click the Review tab. In the Comments group, click Show Comments. A task pane opens, showing all the threaded comments.