How To Pass Variables Between Workflows In N8N

I’m trying to send data from one workflow to another using the “Call Workflow” node (formerly known as “Call n8n workflow tool”). I saw a YouTube tutorial where the node had an input field called “Field to return”, which allowed passing output back from the called workflow to the parent one. However, in the current version of n8n, this field seems to no longer exist.

Now, whenever I invoke a child workflow, it receives an empty object as input, and the “Call Workflow” node in the parent workflow does not return any output either — even though I can confirm the child workflow is being triggered.

How can I properly send data from a parent workflow to a child workflow and get the output back?

The parameters required for the workflow are defined in the When Executed by Another Workflow.
The result of the sub-workflow is the last node executed in the sub-workflow.