How to create multiple variants of a page in page manager
Create a page with the url /brands and add your variants. Use the "String: URL Path" selection rule to manage each one.

How to:

Under selection rules for the main (panel) page add the "String: URL Path" rule with a single line "/brands"

Do the same with the variants but:
Under the first variant use /brands/brand1 
Under the second variant use /brands/brand2
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