Please note that each version of FileMaker released comes with starter solution files that have the same name but different design details. I am guessing that you are using FileMaker 13 for this.
Are you placing these charts on the layout named "Expense Reports" inside the "Desktop" layout folder?
In what layout part are you placing these charts?
The two fields that you describe are fields from the related Data table. What data source options did you select for this chart?
Filemaker Pro 13 Advanced, and the charts are on the expense reports layout found outside of the desktop, iPad, and iPhone layout folders and next to Expense Report List | Printable View, and Receipts | Printable View. I'm placing the charts in the leading grand summary part of the report, and I chose the current found set, but it is sorting by the expense id field instead of the Type | MATCH FIELD.
It will sort by the sort order you impose on the found set via Sort Records. I'm guessing that the sort order that you need for the first chart is different from the sort order that you need for the second. Which leaves you with the dilemma that you can get this to work for one chart or the other, but not both. Please note that when sorting on multiple fields, only the first field in your sort order affects what you see in your chart when using the "found set, summarized data" data source options.
In the current setup, every time an expense is added based on the Type | MATCHFIELD field it creates a new slice in the pie chart instead of increasing the percentage due to the sort order. Would a calculation allow me to add the expense amounts and mileage amounts, which would allow the percentage to grow for only two slices? One of the slices being expenses and one being mileage.
Basically I'd just like to show the expenses vs mileage as a percentage in a pie chart.
In the current setup, every time an expense is added based on the Type | MATCHFIELD field it creates a new slice in the pie chart instead of increasing the percentage due to the sort order.
This issue is your found set's sort order. If you use Sort Records to sort your foundset by Type | Matchfield. And If you have selected the Summarized Data data source option for your chart, you will get a wider wedge instead of seeing a new wedge added to the chart. But as I have already pointed out, this may be a case where sorting your records by this field makes your second chart work at the expense of keeping the first chart from working if they each require a different sort order.