In principle, it's the employee's problem, not the company's
Simply put, your employer doesn't care how you get to work on time, as long as you do. That one employee needs 3 hours to get to work when a coworker might only need 3 minutes is not relevant to the company: they expect you to be on time at the designated place. That's your responsibility as an employee, which you agreed to when you signed your contract.
This means that if you're moving for any reason that wasn't forced on you by your employer, you should not expect them to react to that in any way.
Now, if you were hired to work specifically at location X and your employer decides you need to work at location Y instead causing you to have a much longer commute, only then can you start talking to the employer about some form of compensation. In this case it's the employer's fault that the commute time increased. However, be aware that it's possible that your contract already includes a provision that states you may be asked to work in a different location than location X, in which case you have no real basis to ask for compensation.
Regardless of why, if your commute becomes too long for comfort, the only thing you can do is take steps to shorten it. This probably means either moving houses to live closer to work, or changing jobs to work closer to home.
Another thing to keep in mind is that even if you do get some compensation, that doesn't change the length of your commute. What constitutes too long of a commute is highly personal. Some people will happily spend 3 hours getting to work and another 3 hours getting back home. Other people will get fed up as soon as they need to spend more than 20 minutes to get to work. Nobody can decide for you what commute you're comfortable with, but it's important to keep it in mind when you're making your decision.