Is it possible to limit the Knowledge Agent Query to a specific KB or Document?

Yes, you can specify one document or several.

How? i dont see an option inside the Query KBs Card

Hey, you can't select a specific Kb inside the query KB card. I believe Botpress might introduce this feature in the future. You can try creating folders to limit the KB search 9although I don't think it currently works). Alternatively, you can use a capture information card and select a specific KB there