Interesting question, for on-premise you can use powershell to query the nintex DB to find any reference to that component workflow inside the workflow configurations.

I think the only way you might be able to do it is to go to the Nintex workflow list store where all of the XML is located, find or create a workflow you know has the component workflow configured, then find its specific config in the XML format, then you’ll have to export all of the workflows as XML from that list and then search for the config.

All of this though is theory, I’ll have to test it to see how well it works.

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