Each time you need to transfer money between your accounts you should do this as separate transaction. For example let’s assume you get some cash from credit card- this mean you get some amount from 'Credit card' account and put it to 'Cash' account.
To make this transfer transaction - just add new transaction and select for it some group with type equals to 'Transfer'. In 'Take from Account' field select account you want "to transfer money from"(Credit card) and "amount" you want to transfer.
In 'Put on Account' field select target account you want to "transfer money to" (Cash).