How do I change the topic hierarchy from product to brand?

How do I change the topic hierarchy from product to brand?

I have clicked on the contacts/manage topics - and it shows me product topics are selected - but I don't want this.  Not sure how this was set up.  Even when I click edit on the right side it wants me to add a product.  I don't want to do this I want to change to the topic - brand hierarchy.

thanks in advance