How do I convert my flat list to a tree list when trying to bulk import from Excel 2013 to TFS?

I've got a lot of product backlog items that I want to load into TFS. We've already got most of these defined in an Excel spreadsheet, so I thought that bulk importing from Excel to TFS as described here would be the best way to go.

If I just wanted a flat list, I'd be fine. Excel 2013 is a bit different than the screenshots in that article, but it worked pretty much the same. I went to the TEAM menu option and selected a new list, and then built the list from my selected query. I got a screen with my existing work items that looked like this:

enter image description here

According to the article I linked above, if I want to be able to add sub-tasks I need to convert the flat list to a tree list. I'm supposed to do this "by adding a tree level." However, here's the problem with that:

enter image description here

I've tried clicking in various cells in case something needs to be selected to "enable" this option, but my blind clicking has yielded no luck. Am I just terrible at following instructions, or does Excel 2013 have some quirk that I need to work around?

What do I need to do to enable this so that I can bulk import sub-tasks?

Solution

The Work Item Query you select needs to be a tree-based query. I'm guessing the WI Query you are selecting is a flat-list, that's why those features aren't lighting up in Excel.