The Find Items in Other Sheets and Models is a dockable window that enables you to search for an object across all prepared sheets/models in the Project Browser.
The label at the top of the window indicates the object currently selected in the Scene View. The geometry type is represented with an icon next to the object's name. The icons are the same as the icons used on the Selection Tree window. The search results are displayed in the Sheets/Models list, and contain all sheets/models in the currently open file where the selected object has been found. You can sort the results by clicking the heading of the desired column. This alternates the sort order between ascending and descending.