The same workers, different times into the plant, and fill in the source (source now and in the past) and address (also points the present and the past), how to take the same workers the sources and the number of different addresses (source and current address) is now

When source 2 and 3 are sometimes, how to get source 2 address, if there is no 2 sources, and he took three address (source 2, and 3 address may or may not be the same same)