We would like to setup a DataSource import using transactionID to import offline transaction into a reportsuite.
But the import file also contains records of transaction on products that belong to a different business unit which uses their own reportsuite.
Therefore we would like to import ONLY those rules from the file that have an transactionid that is also recorded during a visit in the reportsuite.
Is this possible directly from within Adobe Analytics?
Or is the only option to build a script that first retrieves all transactionid values from Adobe using the API and filters the original import file based on these before uploading it to the data source import?
This most definitely isn't possible using Analytics alone. Adobe takes all the values in the file and attempts to process them, so you're going to get everything if you upload the file as-is.
If you're able to sanitize the file yourself using an automated process, that could work. Adobe also offers professional services that could certainly help establish an ideal workflow for you. If you'd like to pursue that route, you'd want to get in touch with your account manager.