If I understand the passage correctly, the court-appointed expert is charged with taking the “généralisé compte courant” and spliting it up amonst the principals, assigning each transaction on this account as a credit or debit to the account of the principal to whom the transaction is attributable.

After that mouthful, I would translate the whole passage as follows:

individualize the current accounts of each partner, namely that of M. X, Mr. Y, and Mr. Z, with a detailed list attributing each transaction from the general account as a credit or debit to the individual accounts, said list to include transactions from the date on which the first dividends were declared and not distributed.

There is nothing in the source text that I can see to indicate how each credit and debit is attributed to each account, but I assume it’s based either on the partnership agreement or on the individual partners’ contributions or withdrawals. Perhaps someone with more experience in partnership law can elaborate.