The only way is to creating so called "placeholders", unfortunately it's the only way I know to do something similar - standard variables do not allow to use PQL :| .
Mmm that is unfortunate, because I need to use this in a graph metrics name and the placeholders are not available there. I wonder why Celonis removed this functionality?
As far as I know, this is not (yet) implemented in the enhanced views. Since it is quite an advanced use case, it might be implemented in a later stage, but I have no idea about that.