xpath to select all parents and all children

Question

I need to write 2 xpath queries one of which selects all parents of a specific element from the element's direct parent to the root and then I will be able to select some specific attribute of the elements.

and the other selects all children of an element no matter where they are.

for example if the xml document is something like :

<role key='total-admin'>
    <role key='security-admin'>
        <role key='users-admin'>
            <role key='add-user'></role>
            <role key='delete-user'></role>
            <role key='deactivate-user'></role>
        </role>
    </role>
</role>

1. I want to select all parents of the element with key 'add-user' .the result would be:

   [ 'users-admin' , 'security-admin' , 'total-admin' ]
   

2. I want to select all children of 'security-admin'. the result would be:

   [ 'users-admin' , 'add-user' , 'delete-user' , 'deactivate-user' ]
   

Answer 1

For the first query use:

//role[@key = 'add-user']/ancestor::*

For the second:

//role[@key = 'security-admin']//*