In a conversation or a discussion, talking about a topic that you talked about before is called "going back to ___". For example, imagine a conversation between you and a friend:

1. You talk about your job.
2. Then you ask your friend about his children.
3. Then your friend asks more questions about your job.

In this case, your friend might say:

Hey, I wanted to go back to your job. What were you saying about your boss?

If you're describing this conversation to someone else, you might say:

I asked him about his kids, but thene we went back to my job. So I told him...

A similar phrase is "come back to ___". Use this when you're having a conversation and you know that you might want to discuss a topic again later:

Let's move on, but we can come back to this later if anyone has any questions.