Currently staff can enter a total KM into mileage on a shift to enable invoicing and reimbursement to staff. (See Add Mileage/expense)
This feature allows you to split the mileage over 2 or more participants to only invoice them for their portion of the mileage.
How to split mileage
Open up the shift that has mileage on it you wish to split
Click on Edit > Advanced Edit
Navigate to Invoice Settings
For each participant, click on Expand
You can either toggle off Invoice Mileage or enter the number of KM you wish them to be invoiced for. (Blank = use shift mileage)
Repeat for each participant
The staff will still be paid for the full KMs entered into - this assumes the relevant travel allowance has been attached to the shift.