Hi @Kayla_Arons , I feel you - you may want to vote for this also:
Until if/when Asana decide to implement this change, to help you solve you issue, if you have Advanced or Enterprise, you could create a Portfolio to add all your Onboarding projects into that so that it would be accessible from your Work mode by starring just that. Simply hover over that starred Portfolio to see all Onboarding projects within it, similar to your Team flyout menu.
Assuming your onboarding projects are created from a Project Template, you could go into the project template editor settings (step 3 on the left) and set this portfolio for all new projects to be added to it automatically.
Hope that helps for now.