1. Copy full path from the tab
The simplest way to get the full path to a source file is to open the file in the editor and the right-click the source panes tab. One of the options is to copy the full path
2. Quick way to open another file located in the same folder as an existing  source file
When you have a number of source files opened from various locations it can be frustrating to go through the File->Open and navigation process time and again. One trick is to keep open an existing project file located in the folder you want to navigate to. When you select File->Open it will start in the same folder location as the active file in the editor.