Go to Brand profile which user want to unfollow by searching from global search or find Brand from explore list also.
Click on button following and dropdown will show unfollow the brand at the bottom right corner of the brand cover section.
Brand profile from left drawer explore list by tapping on the top left
corner logo of the community and then go to the third slider. There user
have to tap on the brand and go to the barnd listing.
Click on button following and dropdown will show unfollow the brand.