AppMaker + WCFM Filter by Vendor at App Level

Hi,
Is there a hook or something available that will allow me to filter all information by vendor ID? E.g., VendorA and VendorB are on my WCFM Marketplace website but only VendorB wants app. How do I filter all information going from the website to appmaker app filtered by vendor ID? E.g., all building blocks should show only products and any other details for Vendor B in app. Thanks.