I think this is more of a WordPress mix-up than an L&L mixup. The important thing to realize here is that a “custom category” is not the same thing as a “custom taxonomy.” A category is one of the default taxonomies in WordPress. So if you’re actually working with a “custom category,” that implies that your taxonomy’s data structure looks like this:
category
> category-term
>> child-of-category-term
And since child-of-category-term is just a category term itself, if you wanted to only display posts in that category, your loop might look like this:
<Loop type=mitarbeiter category=child-of-category-term>
On the other hand, if you have a custom taxonomy that’s totally separate from WordPress’ category taxonomy, your data structure might look like this:
custom-taxonomy
> taxonomy-term
>> child-of-taxonomy-term
Again, that child term is itself just a term, so your loop might look something like this:
<Loop type=mitarbeiter taxonomy=custom-taxonomy terms=child-of-taxonomy-term>
And then if you wanted to dynamically refer to the child term in your loop you’d just replace the value of the terms attribute with a local variable, as you sorta did in your example.
I hope that clears up the difference between a category and a custom taxonomy and based on which one applies to you you can choose the right approach above. I don’t think you’ll need to do anything fancy with parents=true or anything like that since it sounds like you simply want to display posts that have that child term applied, so the fact that it might be a child term of some other term doesn’t really matter at all since you’re ultimately just displaying posts that have a particular term applied.
