Concerned mama:
The Watchtower Society breaks every country into sections: zones, districts and circuits. A number of congregations comprised a "circuit" over which the "circuit overseer" had oversight. He usually would visit a congregation about twice a year. Sometimes a congregation would be assigned a "host congregation" for an assembly. Then, a special visit would be made by the circuit overseer sometimes to be joined by the "district overseer." It was suppose to be considered a rare "privilege."
When the Watchtower Society was experimenting with the "elder arrangement" it made some tactical mistakes such as the one previously mentioned. Another one was the idea to rotate the positions of the elders annually in the congregations giving each an opportunity to be "congregation overseer." This turned out to be another disaster. Evidently, the "spirit led" arrangement had a lot to be desired...haha.