wallet-CLI was used to send the transaction, but the sender forgot, where he send the money, so is there a way to determine, where it was sent?
I would prefer wallet-CLI or wallet-RPC solution if there is any.
The wallet file/wallet cache contains the data it used to construct transactions. If you still have the actual wallet file used to spend the funds, then you can open the file with the GUI wallet or CLI wallet and each software will have access to all the data in the file.
If you have lost the wallet file, and therefore you have been forced to recover from seed, for example, the wallet file may not have all the information you desire. The wallet will recognize that it spent funds, and it can identify the tx pubkey corresponding with the spend funds, but it will not have a record of the recipient's public address that you used to construct the transaction.