First of all, you'll need to be an Event Admin in order to do this. 

Passes are grouped in categories. By default Eventree comes with People and Vehicle categories. 

It is only possible to allocate one of each category to someone, e.g. you can allocate Jim one Pass from the people category and one from the vehicle category. For more information on this please see this article.

However, you may need to give someone, for example, 2 vehicle passes, i.e. a build and break and a onsite car pass.  To do this you would need to set up a new category;

1) Click on 'Passes' in the left menu:

2) Then click on 'Add categories':

From here you will be able to 'Add ticket category';

You will now need to add a new ticket type and select 'Build and Break Vehicle Pass' as the category. For more information on this process please read this article.