Write an article based on this "Open your Excel document. Click the Data tab. Click Auto Outline. Minimize your data. Clear your outline if needed."
Double-click the Excel document to open it. It's in the left side of the green ribbon that's at the top of the Excel window. Doing so will open a toolbar below the ribbon. It's in the Group drop-down menu. If you receive a pop-up box that says "Cannot create an outline", your data doesn't have an outline-compatible formula in it. You'll need to manually outline the data. Click the [-] button at the top or on the left side of the Excel spreadsheet to hide the grouped data. In most cases, doing this will only display the final line of the data. Click Ungroup to the right of the Group option, then click Clear Outline... in the drop-down menu. This will ungroup and unhide any data that was minimized or grouped previously.