To see your coworkers in your dream, highlights aspects of your waking relationship with them, including difficulties/support. It signifies your ambition, struggles and competitive nature. If the coworkers in your dream are not your actual coworkers, then they may pertain to some psychological business that you need to work on. Work-related dreams can also often be linked to stress at work.
To dream that you are training someone to take your place suggests that you are moving toward deeper inner development. You are leaving behind old attitudes and are looking toward the future.