The Big Sur version of the Notifications Center is new and improved. I like what Apple has done with it. If you receive many notifications during the day, then you may wish to clear some or all of them out occasionally. Here is how you do that.
If you wish to only clear notifications from a particular app, start by opening the Notifications Center.
To clear the notifications for a specific App, just move your mouse over the upper left corner of the notification.
When you click on “Clear All”, the notifications from that App will be removed.
If your Notifications Center is getting too crowded, you can clear out all notifications from everything and start over. To do that, you have to click on the “More Notifications” button to expand the list.
Now move your mouse over the Notifications Center title and a little menu pops up to the right.
If you click on the ellipsis to the right, the “Clear All” option appears.
When you click on “Clear All”, then all of your notifications will be removed.
You get to start over with notifications.
If your Notifications Center has become a mess of notifications, it might be time to just clear them all out for a fresh start.