It is possible that invited partner eg. AK Brand sells not only own brand products, but also products of other brands (eg. Demonstration). If you would like to expose only partner brand (eg. AK Brand) on all of the products on your marketplace you can reassign them from brand to partner brand.
Go to Products
Click Filters button
In
Partner field
find Partner name & click Filter Results button
Review in Brand column, which products should be reassigned to partner own brand
By ticking checkboxes next to product names, choose which products brand you would like to change to partner brand name.
Bulk edit menu will show up on bottom of the page
Choose from bulk action menu "Add to brand"
Choose the partner brand name
Click Save button to apply changes