How to create filter for when a custom field changes in Asana

We are trying to set up so that when a custom field (called Feature) changes, it automatically gets added to a certain section in Asana.

Before we tackle how to add/update it to the right section, we’re wondering how to first create a scenario that triggers when a custom field changes.

We currently have the beginning of the scenario to “Watch tasks”, specified to modified tasks.
Then we are wondering what the next modules should be. We can see the option of “Get Custom Field”, but that doesnt tell us whether that has changed or not.

@Lewis_AP; I’m not familiar with Asana, yet since webhook is mentioned in the docs, might you modify the custom field to notify a webhook on change?

Then you have a scenario listening to that webhook and perform desired work.