Hello, @Γιώργος Κουκούσης,
The brand filter is essentially a product attribute established in the dashboard under Products > Attributes: https://postimg.cc/mht3y18g . It’s then configured in the sidebar via Appearance > Widgets. Check out this example: https://postimg.cc/pmXLKzJ0 . If you wish to remove the filter, you can do so from there. However, if you want to modify the brand filter, you’ll need to make changes in Products > Attributes as previously explained. I hope this clarifies things.
Best Regards,
PThemes Team.