To get rid of the error, you need to do the following.
When you create a New parameter for a connection, you need to select the "Cloud Integration Hub" connection type:
Validate and save.
When creating a mapping task, define the target connection as Cloud Integration Hub and object as Topic / Application bundle:
For subscription mapping, by analogy with publication mapping, we parameterize the connection and the object for the source node (since for subscriptions the source is always Integration Hub).
Also - for the Target node, we define the connection and the object (no parameters are required!). Exception - in the Field Mapping tab, you need to set:
Next, we create mapping tasks, publications and subscriptions as usual. There should be no mistake.