Depending on your company settings, as an Approver/Controller, you can have the option to edit expenses.

1. Go to Expense > switch role from Personal to Approver/Controller.
2. By default you'll end up in 'To Do'
   
   
3. Select the expense you would like to edit. All fields that are not greyed out can be edited. You can also split the expense if needed.
4. Once you have completed the changes, click Save or Approve.