To filter Sales by Item Report by Account, determine if the Account type is the Income type or not.
Use Sales Transactions > Account > Name if user want to filter the report by Balance Sheet Accounts like Accounts Receivable, Bank Accounts, Undeposited Funds, and Other Asset Type of accounts.
Use Sales Transactions > Account Line > Name if the user wants to filter the report by Income/Expense Account and Deferred Revenue type of Accounts.