Can I create 3 levels of clients and invoice at any level? For example, a client may be divided into departments at the second level and teams at the third.

Good day, jeff-harris.

To clarify, are you trying to group clients to different segments? If so, you can follow these steps:

1. Go to Sales > Clients.
2. Click the Client types button beside the New client button.
3. Select New client type and enter the donor type.
4. Hit Save.

Here's a sample screenshot for a visual reference:

Once done, you can add the client type by following these steps:

1. Go back to the Clients page and select the client's name.
2. Click the Edit button.
3. In the Client Information window, go to the Additional Info tab.
4. Set the client type from the drop-down list.
5. Hit Save.

I've got this sample screenshot:

To learn about about the client types, you can read this article: Set up and assign customer types in QuickBooks Online.

If you're planning to create sub-clients, the steps are included here: Add and manage customers in QuickBooks Online.

Please let me know if you're referring to something else. I'll be around to help you out some more. Stay safe!