First of all you would have to create the relationships between those tables in each class:

// Declare relationships in both models

    
    class Platform extends Model {

        public function priorities() {
            return $this->belongsToMany(Priorities::class);
        }

    }

    class Priority extends Model {

        public function platforms() {
            return $this->belongsToMany(Platform::class);
        }

    }

// Now in your controller you would have to retrieve the value:

    public function getPlatformName($platform_id) {

        $platforms = App\Platform::findOrFail($platform_id);

        foreach($platform->priorities as $priority) {
           echo $priority->name;
        }

    }

// otherExample

    $priorities = App\Platform::findOrFail($platform_id)->priorities()->orderBy('name')->get();

    foreach($priorities as $priority) {
       echo $priority->name;
    }

// Hope its clear enough, for better understanding go to:

• Documentation
• Eloquent Relationships Cheat Sheet
• Eloquent Relationships: The Ultimate Guide
• 20 Laravel Eloquent Tips and Tricks

Good Luck bro!