Thanks for taking the time to reach out here in the Community. I'd be glad to provide some info on your question regarding editing sub-accounts.
There are many ways to modify and customize the look of your Chart of Accounts in QuickBooks Online. The type of edit in your illustration would need to be completed one account at a time. I can show you how:
1. Click the Gear icon in the top right corner.
2. Select Chart of Accounts.
3. Choose New.
4. Select the account and detail type.
5. Click Is a sub-account and enter the parent account.
6. Enter a name and optional display name and description.
7. Enter the sub-account's balance and the "as of" date, if necessary.