How do I create a View filter by a parent taxonomy term? I've got a taxonomy that is set up as such, which I am using with Taxonomy Term Templates:

Manufacturer&gt;&gt;Model&gt;&gt;Colour

Eg:

Honda&gt;&gt;Accord&gt;&gt;Red

I'd like to create a View that displays all siblings of a Taxonomy, eg if I am on the Accord page I'd like the view to return other Honda models (eg: Civic, CR-X, HR-V, Odyssey).

I've tried using the %term:parent as a contextual filter, but have had no luck - no results display.

Would anyone know how I might go about this?
Please follow such steps for getting your result (Child Items)  

1)Add Taxonomy term: Term ID in CONTEXTUAL FILTERS.
2)Add Taxonomy term: Parent term in RELATIONSHIPS. (leave Require this relationship unchecked.)
3)Add Taxonomy term: Parent term in filter section. select great than 0.
4)Do not forget to filter your taxnonmy term in mycase Taxonomy vocabulary: Machine name (= airports).
5)Add Taxonomy term: Rendered Taxonomy term to your fields , select relationship to parent , check the Exclude from display.
6)In setting, under FORMAT section. In grouping field 1, select (Parent) Taxonomy term: Rendered Taxonomy term.  

You should good to go. you can use view tpl to add more class base on the group.
 I have enclose my screenshot for references.