Changing super-navbar-buttons titles

New to AngularJS in Supersonic/Steroids/Appgyver

I know this is not working, but are there some variants that would work:

<super-navbar-button side="left">
    {{ titleButtonLeft  }}
</super-navbar-button>
<super-navbar-button side="right">
    {{ titleButtonRight }}
</super-navbar-button>

while

$scope.titleButtonLeft = "Left"
$scope.titleButtonRight = "Right"

Alternatively, change the title by code on super-navbar-buttons without removing and adding them.

Can't seem to access the buttons specifically with, for example:

supersonic.ui.navigationBar.buttons.right[0]

or

supersonic.ui.views.current.navigationBar.buttons.left[0]

even though they should reside somewhere therein, according to:

http://ift.tt/1EWjBGT

Any suggestions?