The problem with tracking most hardware wallets including the Ledger is that they generate a new address for every transaction and move the holdings.
This increases the protection of privacy, but also increases the difficulty of tracking holdings. If in doubt please contact Ledger directly.
For BTC you have the possibility of using the XPub Key. (Only for BTC and only for future transactions).
This importer (2nd on the "Bitcoin Wallet Import" page) is able to follow your transactions despite address changes. It uploads them in bulk.
Ledger offers a dashboard via a Chrome application, you will find the link to the XPub Key via this browser add-on or on this page, if you use the Ledger Chrome app:
Further information might be available here:
For other coins it is necessary either to upload each generated address once (choose 'Bitcoin Wallet Import', 'Ethereum Wallet Import' or 'Altcoin Wallet Import') or to upload all transactions themselves into the system.