I’ve used both Knime and Dataiku DSS. Although both do data science and show a flow I’m not aware of a way to export an entire Knime flow and import it into a Dataiku project. You may be able to move some of the ML models trained in Knime, using one of the portal model formats PFA and use it in DSS. But I’m fairly sure not the entire flow.
If you are using an enterprise license of Dataiku DSS I’d reach out your customer success manager and share your use case. With more details they may have some more useful ideas about how to proceed.