ORCgrp is a member of PIDgrpgrp and PIDgrpgrp is missing from your "if" statement. The condition should read:

..Contains(..ToUpper(source.{PIDgrpgrp(k1).ORCgrp(k2).OBXgrp(k3).OBX:ObservationValue()}),"DETECTED")

I don't know whether you're using the same doctype for the target, but if you are, the target path will need to be updated as well.

Use a combination of the ToUpper() and Contains() methods in the Function list with an if rule:

The AI Bot offers another option, but it's probably a bit more involved than you really need 😁

The rule parser/compiler doesn't handle calls to methods/classmethods unless they extend Ens.Rule.FunctionSet, and it doesn't recognize the ##class() keyword. If your class does extend Ens.Rule.FunctionSet, you should be able to use just the Methodname as shown below:

<assign property="PropertyName" value="SomeMethod(args)" />