The FolderSizes Scan Data Panel provides a host of useful features, including the ability to find the deepest folder within a given file system node.
To use this feature, first initiate a file system analysis (e.g. by selecting a path in the Folder Browser Panel, entering a path into the Location Bar, etc.). Once the analysis is complete, switch to the Scan Data Panel.
Now right-click a tree node and select the Find Deepest Folder option from the resulting pop-up menu. FolderSizes will find the deepest subfolder of the selected node, and scroll it into view.