Past Business Travel Booking option is not available in the system; you can manage by below options:

• To reflect the Business Travel in Payroll user can mark in timesheet as Business Travel project, If the payroll is not processed
• User can submit the expense claim by selecting 'Non Approved' type of Business Travel in expense claim if any payment need to reimburse for the Business Travel
• In between the leave period if the employee work any of the days as Business Travel then user can manage in leave accrual for getting those days leave eligibility 
• In Attendance the Business Travel details are showing from the Business Travel workflow, so if the business travel is not entered on time it will not reflect in Attendance as Business Travel. User can enter Exceptional Attendance with remarks to avoid showing as Absent in Attendance