Goby, for now, is a single-address wallet, while Chia wallet is a multi-address wallet. It means that Goby only show the balance of the currently used address. We choose the single-address mode because it’s fast and light. If you’re using the same mnemonic words in Goby and Chia wallet, you can transfer the XCH or CATs (like MRMT, SBX…) from the Chia wallet to the address shown in Goby so that you can get the same balance in both the Chia wallet and Goby. However, it may be different again if you send any tx on the Chia wallet, so the best way is to create a new wallet in Goby. We’re already working on supporting multi-address mode. Stay tuned.
You can execute
chia keys add -f 'YOUR_MNEMONIC_FILE' when you have Chia-Blockchain installed and fully synced.