reuse id in template

That's right, but you probably want to use a slug so caps/spaces/etc. don't break your ID:

<ul>
  <li><a href="#<perch:content id="any_slug" type="slug" for="any_id" />"><perch:content id="any_id" type="text" label="Any Label"/></a></li>
</ul>
<h2 id="<perch:content id="any_slug" type="slug" for="any_id" />"><perch:content id="any_id" type="text" label="Any Label"/></h2>

My solution is not good as it's not working at all. Maybe i should investigate slugs that i never used before.

In what way is it not working? Is it not outputting to the page? Are other regions working and outputting?

Thanks Rachel. I did it some other way because i am using blocks and repeaters but this tutorial helped me with the perch_item_index.

My navigation is ok now.