1. Select a prebuilt metric. For this article, we'll be using Google Analytic's "MTD Website Traffic" prebuilt metric
2. Click the metrics settings cog, and select "Edit Metric"
3. Select "Add New Data Source"
4. Select the data source you would like to add. For this article, we'll be using Google Spreadsheets
5. Select the file you would like to call and click "Connect"
6. Go to "Chart Settings," select "Add Data," and select the new data you'd like to see reflected in the chart
7. Format the chart
8. Click "Save"