Get all participant Models that a Model ever had a conversation with

[mooxnl]

I'm trying to retrieve a list of all the Models (participants) that a certain Model ever had a conversation with.

My chat screen has 3 columns:

1. list of contacts (grouped, so each contact is displayed only once and sorted by latest message first)
2. list of conversations with the selected contact
3. messages inside the selected conversation

My question is regarding the first column. Is this possible?

I tried it with this query to get all participants for User with id 1, which works, but doesn't group the participants:

Musonza\Chat\Models\Conversation::query()
    ->whereHas('participants', function($query) {
        $query->whereHasMorph(
            'messageable',
            [User::class],
            function ($query) {
                $query->where('id', 1);
            })
            ->groupBy(['messageable_type', 'messageable_id']);
    })
    ->get()