Are you trying to network "up"? Are you looking to network with people who are higher up in the corporate structure than you, own bigger companies than you, or who have more resources than you?
It's not a bad thing to want to do. If you're a B2B salesperson, you need to make sure that you are in touch with the business owner. If you're looking to move up the corporate ladder, you need to find out what it takes to be in that position of higher responsibilities. If you have no resources, you need to partner with people who do have them.
But ... I find a lot of people who don't know where to find such people and who don't know how to approach them. They get frustrated because they don't think they see them in the organizations they are part of, such as the Chamber. That's both true and not true.
It's true because you will find more people who are in sales participating in networking activities such as mixers. Business owners of larger companies tend to not go to what they see as social events for a couple reasons: first, that's what they have a salesperson for - to specialize in building relationships and finding prospects; second, they are more focused on issues such as government regulation and don't see the benefits of the networking specifically for themselves. Plus, they can find themselves beseiged by salespeople when they do attend.
The business owners do participate, they're just more selective. And it's not true that you can't reach business owners if they don't attend, because those salespeople who to to events have great contacts with other business owners that they might be willing to share with you - if you share with them.
I can't recall where I heard it said that a salesperson is the best contact you could have with a company. They are informed and involved with their business. They know how to work with decision makers. And - if they decide that you're product is a benefit to them - they are a great advocate to help sell the idea internally!