Please find the below link
It will be help you create countd on blended data source. Hope this helps
Plz mark this answer as correct or helpful to close the thread
Could you share your workbook in -tbwx format so the community gets an idea our the data is structered?
I am keep getting the error that the data can't be blended with the other source, even though the calculation is valid..
Since this is live customer data I can't share unfortunately
You can create a tableau packaged workbook with dummy data (manually type in some data in excel) and upload the .twbx here.
Please create an sample extract and share the twbx file with both sources so that it will be easier to help. If that is not possible then replicate your situation with the help of another dataset and share the file.
CountD doesn't work with blended data sources and there are various limitation of using LOD along with blended data sources. Therefore in order to provide some solution/workaround we need your data/twbx.