A key generator tool by iancoleman can generate EIP2333 keys from a BIP39 mnemonic, or a seed, or a master secret key.
This tool should be used offline and is useful for extracting withdrawal keys and signing keys.
Link: https://iancoleman.io/eip2333/
{% hint style="info" %} For more info see the EIP2333 spec. {% endhint %}