How to reference a user related to entry input in if statement

Question

I am having trouble referencing a user in an if statement:

{% set otherEntry = craft.entries().section('other').userFieldInOtherEntry("{externalVariable}").one() %}

{% if currentUser is relatedTo(otherEntry) %}
    do something
{% endif %}

I've tried using the for loop method described in the Craft 3 documentation, but I get a recursive loop error.

Answer 1

You could do:

{% set otherEntry = craft.entries().section('other').userFieldInOtherEntry("{externalVariable}").one() %}

{% if currentUser in otherEntry.userFieldInOtherEntry %}
    do something
{% endif %}

Answer 2

I ended up having to go through a for loop checking if the user is related to the current entry, then if statements inside of that for loop. Is there a cleaner way to do this?

{% if currentUser.isInGroup('userGroup') %}
<p>My Things:</p>
{% set relatedThings = craft.entries.section('things').relatedTo(currentUser) %}
<ol>
    {% for rel in relatedThings if rel.createdFieldinThing == externalVariable %}
    <li>{{rel.title}} - {{rel.createdFieldinThing}}
        {% if rel.createdFieldinThing == externalVariable %}
                the current user is in the thing
            {% else %}
                the current user is not in the thing
            {% endif %}
        {% endfor %}
    </li>
</ol>
{% endif %}