It doesn't look like liberation is possible other than Bhuloka. Vishnu Purana, Book 2, Chapter 3 says that world of acts is not the title of any other portions of the universe means only fruits of Karma can be obtained in Bhuloka.
THE country that lies north of the ocean, and south of the snowy mountains, is called Bhárata, for there dwelt the descendants of Bharata. It is nine thousand leagues in extent, and is the land of works, in consequence of which men go to heaven, or obtain emancipation.
From this region heaven is obtained, or even, in some cases, liberation from existence; or men pass from hence into the condition of brutes, or fall into hell. Heaven, emancipation, a state in mid-air, or in the subterraneous realms, succeeds to existence here, and the world of acts is not the title of any other portion of the universe.
