Perhaps you need to use a different wallet like Electrum? You should be able to create a new wallet in Electrum using the "Use a hardware device" option... that will import your ledger nano s wallet (public keys only of course!
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Then you can either use "Wallet -> Show Addresses" or "Wallet -> Show coins"... and from either one of the Addresses or Coins tabs, you select the one you want to include in a transaction, right click and select "spend from" for an address... or "spend" for a particular coin.
You should probably be able to do the same thing with ElectronCash for your BCH