Can I add more contact drop downs on the main menu bar or is person type the only way to break it down?

Lets say for example that I have two types of contacts - buyers and sellers. I know that I can label each under person type, however I would prefer to have them in the main menu area instead. For example, where there is the contact drop down I would like that to say “buyer contacts” and then have the same drop down option next to it that says “seller contacts”. Is this possible and how do I do this? I have replicated what I want in the image below

Not on the Main Menu, but you can add a Dashboard Widget and include a Saved Search for each group to quickly and easily take you to the individual lists.