Can a user from one office check the clients of another office?

A user can check the clients of another office if they are given the correct permission.

For this, the user should have the other branch office as a Secondary Office. To do so, go to the user's edit page. You will see the Secondary Office field. Here you get the option to assign a selective number of branches or offices to the user.

Then in the user's Permissions tab, you will need to select the permission "Can view all the clients of all the associated offices. Can assign clients to any users of the associated offices, respectively." and update.