Possibility of nested/consecutive backreferencing in an AQL filter

Hello Ataccama Community, 

I have a question regarding the possibility of using nested /consecutive backreferencing into an AQL filter . 

The actual question would be whether if we can create a filter on the ‘term’ entity to show only the terms which have 0 termInstances on rules . This was the initial issue because we have used this AQL Filter into a Term Report Page : @termInstance(target).count( )==0 . However, this was not enough because it did not filter only the term instances from the rules, but also the ones from the catalog item , attributes , etc. I have initially tried to place something like this : @rule.inputGroups.inputs.termInstance(target).count() = 0 , but I got an error and I am not sure if nested backreferencing is possible .

After that, we changed the approach and we decided to add another entity ‘termsUsedOnRules’ and I configured it exactly the same as ‘termInstances' .

Then I have added this entity as a property on the rule as an Embedded Object Array and filtering based on this entity was possible : @termsUsedOnRules(target).count( )==0.

However, for future implementation, the question still remains : is nested/consecutive backreferencing possible ?

Thank you and best regards,

Serban