Set the "People" Database with one row for each person on the trip/roommate, etc.
Make it fun! Give each person a custom emoji.
As you have new expenses, add them to the "Expenses" database. The payer goes in the "Payer" column (duh!) and anyone who the cost should be split with (including the payer) should be added to the "Splitting" column.
And that's it! As you do this, you'll see the totals updated for people in the "People" database.
The "Amount Paid" is how much money each person has spent.
The "Expenditures" is the sum of what each person owes based on the expense splitting
The "Dollars Owed" is simply the difference between these.
Once all expenses are added, anyone with positive dollars owed needs to pay in that much money. People with negative dollars owed should receive those payments.
Ideally we'd be able to say who should pay whom when more than one person is owed money, but that's a bit tricky to do algorithmically. We'll leave it to you to figure that out!
Lastly, feel free to edit this for your own purposes! Don't trust the people you are going with? Add a "file" column and have people upload receipts.