All objects in your estimate are displayed in the Estimate Tree which resides on the left side of the estimate view. It has a several pieces of information it uses to make up a node which lets you sort and organise your estimate and create folders to make subtotals.
Subtotals are calculated for each folder you add to the estimate. If you wish to be able to see a certain aspect or part of the estimate isolated the best way is to create folder and add objects to it . To see the subtotal, you select the folder itself. You can make changes to all objects in a folder from having selected the folder.
Objects containing negative values for a row in either amount or price fields will give a warning in the tree to let you know that there’s something here you might need to be aware of. If the warning circle is filled it means, it’s that specific object that has the negative value. A non-filled circle will indicate that there is something in the path below in the hierarchy that has the error.