Group posts by ID or distinct, unique posts

Hello,

I’ve got 2 connected CPTs: Project and Testimonial, it’s a many-to-many connection.

I’ve got the following situation where I want to select all the projects that have got testimonials connected. However, if there are multiple testimonials, let’s say 3, are connected to a project then I end up having that project in my results 3 times.

I want to select unique / distinct projects in case there multiple testimonials are connected to it.

Is there a way to do it? To choose unique / distinct posts or group them by ID? I can’t figure out.

Here is what I’ve got so far:

$args = array(
		'post_type' => 'project',
		'order' => 'ASC',
		'orderby' => 'menu_order',
		'posts_per_page' => -1,
		'connected_type' => 'project_to_testimonial',
		'connected_items' => 'any',
		'connected_direction' => 'to',
		'post__in' => <ids_of_specific_projects>,
	);

I would hugely appreciate any tips and pointers.

Many thanks, Dasha

https://www.ads-software.com/extend/plugins/posts-to-posts/