The company ran by Bob and Tom, who is a father of four, closed during the recession.
Ok let's break this sentence into its parts:
a)The company closed during the recession.
b) The company was
run by Bob and Tom - reduced to a past participle phrase in the original sentence
c) Tom is a father of four(wow! 4 kids and still runs a company)
a) + b) have been combined to: The company closed during the recession + The company was
run by Bob and Tom = The company ran by Bob and Tom closed during the recession
Now add c) to the sentence derived above after making (c) a non-restrictive modifier: non-restrictive relative clause
remove Tom from C and make it: who
The company ran by Bob and Tom,
who is a father of four, closed during the recession
Let me know if you have questions. I don't mind kudos