Get children of multiple entries

Question

I'm sure this must be simple but I've tried multiple options with little success. What is the best way to build a query to get the children of more than one entry via an entry field?

For one parent would be:

{% set parent = craft.entries.id(parent_id).one() %}
{% for child in parent.children.all() %}
//Stuff
{% endfor %}

But I cant work out how to build the initial query to include more than one parent entry. The output I am looking for is a query that allows me to loop through all of the children from both(or more) entries selected. eg:

{% set query = craft.entries.id([4,35]).all().children.all() %}

Any help much appreciated!

Answer 1

There's a method available to all element queries called getDescendants() (or like any method in Yii you can omit the get prefix and use descendants()):

{% for child in craft.entries.id([4,35]).descendants().all() %}
    <pre>{{ dump(child.title) }}</pre>
{% endfor %}

You can also pass in a distance integer if you want to limit to direct children/grandchildren.

https://craftcms.com/docs/4.x/elements.html#methods

Answer 2

Why don't you get the children from each entry individually and then merge them together like so:

{% set childrenOne = craft.entries.id(entryID).one().children.all() %}
{% set childrenTwo = craft.entries.id(entryID).one().children.all() %}

{% set allChildren = childrenOne|merge(childrenTwo) %}