Two modes are provided for the cell list: a tree view (the default) and a flat cell list. To switch to flat mode, check the "Flat Cell List" option in the cell panel's context menu.
If multiple layouts are loaded, the cell lists of the individual layouts are shown separately. The drop-down box above the cell lists will select the current cell tree to show. An alternative mode is available in which the cell lists are shown beside each other in the cell tree panel. This mode is enabled by choosing the "Split Mode" option in the cell panel's context menu. In split mode, you can click on the headers to select the current cell tree. The current cell tree plays a role in some cases, for example for the layout operations available in the "Layout" submenu of the "Edit" menu.
In addition, three sorting modes are provided: alphabetically by name and by cell size (bounding box area), descending and ascending. The cell size is supposed to reflect the design level: library and leaf cells are usually small which macro blocks are usually large. By using cell size sorting in ascending order, the leaf cells will be shown first. To change the sorting, check the corresponding option in the "Sorting" submenu of the cell panel's context menu.