Getting ancestors for manually set parent in template

Question

I have a a few pages outside of a structure but I want to display a breadcrumb for it as part of a structure. I am currently setting the parent page like so: {% set parent = craft.entries.section('pages').slug('phone-directory') %}

{{ parent.ancestors }}

But when I loop through to get the ancestors it is only getting the current parent not all ancestors? Any idea how to achieve this?

The structure is
Staff
    Phone Directory

The reason I am trying to do this, is the 3rd level pages are either category pages or is a single with some specific routes. I want to manually set the real parent in the template, so I can get the ancestors for the breadcrumb trail as though it is part of the same section.

How can I manually set the parent entry in the template and get the ancestors from this entry?

**** UPDATED ****
This is an update on the above to show my exact code and what isn't working and How I expect it work...If anyone ca shed some light?

So by default I am getting my breadcrumbs like so;

{% if entry is defined and entry.section.handle != 'homepage' %}
{% set crumbs =  parent.ancetors ?? entry.ancestors|default([]) %}
{% set crumbDivider = '<li><span class="mx-3 text-grey text-xs">/</span></li>' %}
<nav class="mb-8 mx-6">
  <ul class="list-reset flex flex-wrap items-center text-grey-dark text-sm">
    <li class="mr-3 text-xs text-grey-light">You are in:</li>
    <li><a href="{{ siteUrl }}">Home</a></li>
    {% for crumb in crumbs %}
    {{ crumbDivider|raw }}
    <li>{{ crumb.getLink() }}</li>
    {% endfor %}
    {{ crumbDivider|raw }}
    <li class="text-grey-darker">{{ entry.title ?? category.title }}</li>
  </ul>
</nav>
{% endif %}

This works as expect for normal standard entries. For example, within my Pages structure I have a parent of News with a Child of Internal News and on the Internal News page, the breadcrumb is reflected as; Home / News / SWH Internal News

Now on the news entry pages I want the breadcrumb to read as follows; Home / News / SWH Internal News / {{ Entry Title }}

I thought by setting the parent on the news/_entry.html template to the SWH Internal News page like so; {% set parent = craft.entries.section('pages').slug('archive') %}

Would then give me the ancestors of News / SWH Internal News but instead it only outputs SWH Internal News.

Answer 1

As @Robin Schambach said, you need to loop through the ancestors.

{% set parent = craft.entries.section('pages').slug('phone-directory') %}
{% for ancestor in parent.getAncestors() %}
    {{ ancestor.title }}
{% endfor %}

This won't output the Phone Directory entry since you're just looping through its ancestors. So to complete the breadcrumbs you'll need to add {{ parent.title }} after the loop.

Answer 2

After much help and direction form @RobinSchambach (much appreciated). I have resolved this as follows;

{% set currentPage = craft.entries.section('pages').slug('archive').first() %}
{% set currentAncestors = currentPage.getAncestors.find() %}
{% set crumbs = currentAncestors|merge([currentPage]) %}

{% if entry is defined and entry.section.handle != 'homepage' %}
{% set object = crumbs ?? entry.ancestors  %}
{% set crumbs =  object %}
{% set crumbDivider = '<li><span class="mx-3 text-grey text-xs">/</span></li>' %}
<nav class="mb-8 mx-6">
  <ul class="list-reset flex flex-wrap items-center text-grey-dark text-sm">
    <li class="mr-3 text-xs text-grey-light">You are in:</li>
    <li><a href="{{ siteUrl }}">Home</a></li>
    {% for crumb in crumbs %}
    {{ crumbDivider|raw }}
    <li>{{ crumb.getLink() }}</li>
    {% endfor %}
    {{ crumbDivider|raw }}
    <li class="text-grey-darker">{{ entry.title ?? category.title }}</li>
  </ul>
</nav>
{% endif %}