How to edit welcome_navigation snippet in header

Hey there,

I was wondering if it is possible to edit how the Agent Portal, Edit profile and Sign out links in the navigation are rendered. I can see that this is generated by the following lines in the header;

<nav class="banner-nav">
       {{ portal | welcome_navigation }}
</nav>

I have no idea if this is a) possible and b) where to find the ‘welcome_navigation’ snippet.

Any help much appreciated.