Article in English: Be clear in what you do and who else is involved in the work you do. Schedule a meeting with your manager and go over what’s expected of you. Then, clearly assert the work you do as your own. This can help clear misunderstandings and clarify roles.  This way, you can be clear in any misunderstandings with your coworker. Say, “That’s part of my responsibilities, not yours.” Consider scheduling a meeting with your work group, too, and going over the responsibilities that everyone involved has been assigned. This will help clarify your own and everyone else's roles. Talk to your manager about having some time to discuss your work at meetings. You can make a presentation or update your coworkers on any changes you’ve been making. This allows you to inform people what you’re working on. Give people time to ask questions and gain understanding of what you’re doing. Throughout your speaking time, remain confident in portraying the work you’re doing. If anyone chimes in, say, “You can ask questions or make comments at the end.” If you’ve tried different methods to get the person off your back and they haven’t worked, try talking to someone in more authority. Let them know what’s going on and, more importantly, how it’s affecting your work. Ask them for advice or how to move forward. If necessary, ask them to intervene. Say, “I need some help. There’s someone who keeps trying to take over my work and I’m not sure how to handle it. Do you have any advice on what to do?”

Summary in Indonesian:
Definisikan peran Anda. Bersuaralah ketika rapat. Bicaralah kepada manajer atau atasan Anda.