Another way to navigate to code when a live process exists is to “walk the call stack,” using the stack commands to view functions currently on the call stack that represent all currently active routines. Walking the stack causes the current function and file to change each time you display a stack function. The stop location is considered to be at the “bottom” of the stack, so to move away from it, use the up command, that is, move toward the main or begin function. Use the down command to move toward the current frame.
For more information see Walking the Stack and Returning Home.