Are you able to share your workbook? Have you created any parameters yet? Thinking we could use a parameter inside of a calculated field to help, but not too sure without seeing the data.
Agree that you need to share more information and if possible your workbook as a packaged TXBX workbook - also you said you have 2 data sources - how are the connected - through a join or a blend? and on which fields(s) are they joined