To avoid accidentally making entries on the wrong branch, we recommend that you add a different user when you add a branch, and always use that user when doing day-to-day tasks.
However, if you have an owner-level account you will be able to see the data in all of the branches. If you have access to more than one branch, you'll see a "Switch branch" button at the top of the side bar.
Click it to open up the switch branch menu.
From the switch branch menu, click on the branch you want to view the data in. Once you do, you'll notice that the branch name next to the home icon has changed to reflect the branch you chose from the menu.