Say I have two folders in my Sublime project: folder_a and folder_b, both containing files with definitions for a toString() function.
navigate_to_definition then only lists the files from folder_a when invoked from a file residing in folder_a. The same goes for folder_b.
What would be more natural, and what Sublime does when pressing F12, is to look in ALL .tags files present in the project folders and present ALL occurrences in the dialog.