Merge HasMany relations

[proart]

Hi,
I need to display merged hasMany relations on one HasMany field. How can I do this?

Entry A:

id	title	MAIN_category_id	SECONDARY_category_id
1	A	10
2	B	23	10
3	C	41

Categories:

id	title
10	box
23	circle
41	triangle

Related entries for Category "box" (id 10) should display 2 related entries A (id 1) and B (id 2).

// Resource:
class CategoryResource extends Resource
{
    public function fields()
    {
        return [
            HasMany::make('Related main entries A', 'MAIN_EntriesA', EntryA::class),
            // How to combine fields above and below into one table ?
            HasMany::make('Related secondary entries A', 'SECONDARY_EntriesA', EntryA::class),
        ];
    }
}

// Models:
class EntryA extends Model
{
    public function MAIN_Category(): BelongsTo
    {
        return $this->belongsTo(Category::class, 'MAIN_category_id', 'id');
    }

    public function SECONDARY_Category(): BelongsTo
    {
        return $this->belongsTo(Category::class, 'SECONDARY_category_id', 'id');
    }
}

class Category extends Model
{
    public function MAIN_EntriesA(): HasMany
    {
        return $this->hasMany(EntryA::class, 'MAIN_category_id', 'id');
    }

    public function SECONDARY_EntriesA(): HasMany
    {
        return $this->hasMany(EntryA::class, 'SECONDARY_category_id', 'id');
    }
}

I tried to use packages:

• https://github.com/korridor/laravel-has-many-merged
• https://github.com/topclaudy/compoships

Also tried next line instead of $this->hasMany(EntryA::class, 'MAIN_category_id', 'id');:

$this->hasMany(EntryA::class, 'MAIN_category_id', 'id')->union($this->hasMany(EntryA::class, 'SECONDARY_category_id', 'id')->toBase());

But Nova field "HasMany" doesn't work with this solutions. So how to solve this problem in Nova?