1. Bruce practiced law in a small law firm, then taught law at a university, then gave up teaching and is practicing law again. He has come full circle.
2. We started with a small, two-bedroom house, but as the family grew, so did the size of the houses we moved into over the years. Now that the children are grown and have left home, we’ve come full circle and are moving back into a small house.

The expression suggests that in creating a full circle, one returns to the starting point.