To split an expense in Xpenditure, you open the expense and you click the 'Split expense' button:
You can now fill in the sub amounts and choose the relevant categorie (and/or tax rate - if applicable). To add more sub amounts, click the + symbol:
You can save the expense at this point and the sub amounts with their different categories will be visible within that expense. You can still clear the split if needed until the point when you submitted the expense for approval (if applicable).
On the other hand, if you need to provide more/different information per sub amount (date, payment method, comments, projects, etc.), you need to create separate expenses from the sub amounts.
To do so, you use the 'Create separate expenses from the split expenses below' checkbox:
A date field will appear and if you save the expense at this point, the result will be 3 expenses based on the sub amounts:
Note: depending on the settings of your Xpenditure account, it is possible that you can only split an expense in separate expenses.
Note for Admins: if you want the split expense to always create separate expenses, do not forget to activate this option in the Company settings / Advanced settings: