If you have office expenses for more than one location, you may report the totals as Job-Related Employee Expenses. It's not necessary to separate the two locations for tax purposes.
- Where do I enter job-related employee expenses? (Form 2106)
- Where do I enter the employee home office deduction?
- IRS Pub 529 Deductions Subject to the 2% Limit
If these are offices for your self-employed business, include the costs as Business Expenses (Office Expenses) on Schedule C. Again, there's no need to separate the locations. Schedule C is found under the Business tab.