What is a Secondary office and how to add one?

When a user works in multiple office, other than his/her primary office, such offices are called secondary office. To add a secondary office,

1) Go to 'Teams' & select 'Users'.

2) Now go to the profile of the user and click on edit.

Note: The user or role to whom the access to the secondary office is to be given should have given the permission as marked in the screenshot:

3) Scroll down the page to 'Office Details'. Add secondary office and update it.