I need to split my datasets based on my own feature column in order to hold together certain data rows (e.g. from one patient, or compound) for cross-validation (CV).
In Orange 3.11, Test&Score contains "Cross validation by feature", but it is disabled. The widget documentation contains a screenshot still without it.
Is this a feature that is currently under development? Or do I have to define the relevant column differently to enable the option? (It's "meta" right now.) Or is there a different way to achieve this particular CV, i.e. use a pre-defined column for a "Leave-group-out" CV?