[bluGill]

That very much depends. Different companies work very differently. The important part is the hiring manager believes the person who referred you thinks you are good.

The best way to use your network in all cases above though is reach out to everyone. You never know who in your network has the right connections to help - but they do know. I know of cases where all the hiring managers (4 different managers) ask one person who to hire, if you already had reached out to that one person he will give them a resume and you are hired (note that no jobs were ever advertised, it was either this one person said who to hire or it went to an external 6 months contract to hire company). In small companies everyone talks to everyone, so just reach out to them. In very large companies you need to know someone who knows the hiring manager.

In all cases your contact will know better than you what to do. So ask them.