A cost center is used to allocate costs within a business. Consult with your financial department which names are preferred and create the cost center(s).
Go to Settings > Meet and choose Cost centers from the sidebar menu. Add a new cost center by pressing the blue 'Add' button in the top-right corner.
In Settings > General you can enable the cost center by selecting Optional or Required / Required with confirmation.
In Settings > General there is another option Allow free text input on cost center. With enabling this option, the Cost center field will be writable and the organizer of the catering can insert other text then the proposed Cost center options: