To create sub ledgers and link with main ledger, first you need to enable that feature in BUSY by following these steps:
Step 1: Go to Administration then click on Configuration.
Step 2: Select Features / Options and click on Accounts Tab.
Step 3: Enable the feature called Maintain Sub Ledgers and save.
Step 4: Next, go back to Administration menu and click on Masters.
Step 5: Select Account then Add, and enter all the necessary details such as Name, Group, Address, etc.
Step 6: You need to mention the Ledger Type as Sub Ledger and specify the main ledger.