If you mean transforming/converting Java to bedrock you may use chunker ,but remember that it cannot perfectly functioning because the bedrock and java are very different in terms of their commands .java are for PC while bedrock for android.

But if you mean how to import bedrock edition you can use zarcher
Just for example the given video below

If you are using android phone download zarchiver ,later I will share you tube video how to import world using zip files ,