I use company lists on a daily basis and most of the time what I have to do is to filter specific companies based on properties, which work fine. However, when it comes to creating a list of the CONTACTS associated with said companies, it's incredibly painfull.
There is no straight way of going from a company to it's associated contacts, and I think that this should be an easy and intuitive option available on hubspot.
For example. You created a list with all the insurance companies in your region. There SHOULD be a button to "Get Contacts" or "Create a contacts list" of those exact companies.