On Substrate, each passphrase can be used to create a wallet across different chains: you can store XOR and ACA, for example, using a single passphrase.
However, It may be the case that you're holding your parachain tokens in wallets created using different seeds. On Fearless Wallet, the Unique Secrets feature allows you to see your tokens that are held by accounts with different seeds in one intuitive interface.
To learn how to do this, watch the tutorial below:
Please note that you're replacing an existing wallet on that specific chain with a new one, and you won't be able to see the tokens held in the previous account anymore in the user interface.