Associating the Expense record with your approved Business trip record can be done in a single click.
During the process of adding an expense, when you choose the date of the expense, it's Sage HR automatically checks whether you've approved time off record on this same date. If a time off record is found, such as a business trip, you're asked if you would like to link them together.
When someone submits an expense associated with a time off record, an expense approver receives an email with a link to the expense.
When you view the expense, when you preview the expense, you can see the linked time off in the expense card.