Hello,
Is it somehow possible to put a ACL on the tasks so we can choose based on AD membership if a certain task is visible yes or no per domain?
No, there is no such possibility.
Will this option be on the roadmap if it is not possible?
Yes, we already have this option in our Product backlog.
If this is not possible what is the recommend way?
Currently, there is no possibility to achieve what you need rather than creating a separate Web Interface per domain.