As far as I know groovy has no such mechanism. I suppose You write Your own DSL for that but I see it as rather complicated (and prone to DB scheme changes) and don't know if the game is worth the candle.
If You don't like using ORM tools (I also always hesitate to use them) maybe try something that isn't an ORM tool but helps to avoid plain SQL in groovy code: jOOQ (as far as I know there's no relationship handling in jOOQ). Haven't used it yet but still want to try.