The create automatic group dialog does allow for relevance expressions for group definitions. This is the only option I ever use to create automatic groups. It should be the first or second option.
Also, I wouldn’t recommend creating a property with that relevance, as it won’t be accurate. It is fine for testing the relevance, but you can’t really ask a client to evaluate a time from now because it will only be correct the very instant it reported that, then it will be wrong until it reports it again.
That relevance will work just fine for an automatic group.
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