The display in the Call Stack view depends on which thread has the focus. That thread is highlighted in bold in the Processes & Threads view. To change the focus, and therefore the stack display, double-click on a different line in the Processes & Threads view

The Call Stack allows you to trace back through the execution of the thread in focus. If the left column shows a language, source code is available, and clicking on that stack entry displays the source code in the Source view at the location of the named function. If no language is shown, clicking on the stack entry displays “No Source Available.”

The Local Variables view displays variables associated with the selected frame, while the Registers view (another tab next to the Local Variables view) displays general purpose and floating point registers.