Related Projects (Structure + Channel Matrix) I've looked around a good bit to see if I could solve this problem on my own. I've managed to get close I believe, but I think I don't quite understand Craft's relationships.

Basically, I have a related projects section on my site. I'm allowing the user to select the related projects with an Entries tag within my matrix. I would then like to compare their selected Entries with projects already added to a Structure - then output attributes that exist only in the Structure.

This is as far as I've gotten:

My Structure Content

{% for entry in craft.entries.section('homePageBanners').limit(3) %}
    {% for block in entry.banner.limit(3) %}

        {{ block.client }}
        {{ block.bannerImage }}

    {% endfor %}
{% endfor %}


My Matrix Entries Block:

{% for entry in block.projectsEntry %}
    &lt;a href="{{ entry.getUrl() }}"&gt;{{ entry.title }}&lt;/a&gt;
{% endfor %}


I'm not sure how to compare them &amp; pull content based on what the user selects. I looked into relatedTo(), but didn't have much luck with that.

If that's not clear, I can try to be more specific -- please go easy on me, I'm pretty new to Craft.

EDIT:

Maybe this will help clarify
    {% for entry in block.projectsEntry %}

 {% for project in craft.entries.section('homePageBanners').limit(3) %}
  {% set relatedProjects = craft.entries.section('homePageBanners').relatedTo(project) %}
   {% for project in relatedProjects %}
    &lt;a href="{{ project[0].getUrl() }}"&gt;{{ project[0].title }}&lt;/a&gt;
   {% endfor %}
  {% endfor %}
 {% endfor %}
I'm not sure I totally understand your issue, but give this a try in your Matrix code: 

{% for entry in block.projectsEntry %}
    &lt;a href="{{ entry[0].getUrl() }}"&gt;{{ entry[0].title }}&lt;/a&gt;
{% endfor %}


Are you getting any errors in devMode?