Can 2 sub categories under Sales share same inventory? Can i define the sales from a specific customer to a sub category of sales (e.g. sales - wholesale)

Hello there, janniemui-jmcwil.

If you're referring to adding a Category to an inventory item, you can only assign one category to each product. If you want to link the other category to the same item, you can create a new item.

Here's how to add a category to an item:

1. Go to the Sales menu and click Product and Services.
2. Click New to add a new item or look for the existing item and click Edit.
3. Under the Category drop-down, you can click Add new and enter Wholesale as the name. Click Save.
4. Once you've filled out the item's information, click Save and close.

If you're referring to the Sales account having sub-accounts, yes you can create two under it. Still, you can only associate one income account for each item. You can follow these steps on how to create sub-accounts.

1. Click the Accounting menu and select Chart of Accounts.
2. At the upper-right, click New.
3. Select the correct Account Type, Detail Type, and Name of the sub-account.
4. Check the Is sub-account box and select Sales as the parent account.
5. Click Save and Close.

Feel free to check out these articles on how to handle your items and accounts: 

• Set up and track your inventory in QuickBooks Online
• Create subaccounts in your chart of accounts in QuickBooks Online
• Common custom reports in QuickBooks Online

Any additional information about your question can further help me walk you through the correct steps. I'll be around the corner to keep an eye on your reply. Take care!