Correct. Assuming you are using the out of box groups and categories, perform the following.
1. Access the Project Manager group
2. Select the My Projects category and take a picture of all of the selected checkboxes in the Project section
3. Now add the My Organization category and select it
4. Check all of the same checkboxes that the My Project category had checked.
Your PMs will now be able to access and manage any project. Hope that helps…