I dream that the person I like is chatting with my brother.

Since you are the person you like, don't call him by your boyfriend. There should be no definite relationship. Maybe he didn't become a lover with you, but you like him and want to get in touch with him, but you don't know how to get close to him. It would be better if someone helped you.

You should have a good relationship with your brother. You think he will help you.

So you dreamed that they were together.

Dreams only reflect the existence of people's inner activities, and they come from whatever they want.

I'm not sure I can guess your psychological activities, but the basis is correct. You can imagine what you were thinking at that time, and whether it is relevant, so you can understand.