IDE Window: Code Explorer
The code explorer shows a pascal file as two trees. There are two pages Code and Directives. The Code page shows the pascal structure - types, variables, constants, classes, etc and since 0.9.27 the Code Observer. The Directives page shows the compiler directives structure - $IFDEFs, $DEFINEs, $INCLUDEs, etc.
Double click on the nodes to jump to the corresponding position in the source.
Hint: The code explorer is a floating window. That means you can leave it open and switch freely between other floating windows like the source editor or the object inspector.
Click on this button to rebuild the Code Explorer treeview, forcing the unit currently shown in the source editor to be reparsed. This is useful if you have made changes in the Editor since first opening the Explorer window, and you don't have the option to refresh On Idle set.
Open the dialog to setup the options of the code explorer. See IDE Window: Code Explorer Options.
Filter (text field above treeview)
For example 'to' will show all identifiers containing 'to'. Like 'Button', 'IntToStr'.