what should i do to get a model with similar relationships?

You’re going to want the ‘many to many’ eloquent relationship.

https://laravel.com/docs/8.x/eloquent-relationships#many-to-many

Also checkout:

https://laravel.com/docs/8.x/eloquent-relationships#defining-relationships

In the Candidate model

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Candidate extends Model
{
    /**
     * The Availability that belong to the Candidate.
     */
    public function availability()
    {
        return $this->belongsToMany('App\Models\Availability', 'availability_candidate', 'candidate_id', 'availability_id');
    }
}

Then in the availability model

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Availability extends Model
{
    /**
     * The Candidate that belong to the Availability.
     */
    public function candidate()
    {
        return $this->belongsToMany('App\Models\Candidate', 'availability_candidate', 'availability_id', 'candidate_id');
    }
}

    /**
     * The Job Offer that belong to the Availability.
     */
    public function jobs()
    {
        return $this->belongsToMany('App\Models\Jobs', 'availability_job_offer', 'availability_id', 'job_id');
    }
}

Then in the Job model

class Availability extends Model
{
    /**
     * The Availability that belong to the Job.
     */
    public function availability()
    {
        return $this->belongsToMany('App\Models\Availability', 'availability_job_offer', 'job_id', 'availability_id');
    }
}

Finally to retrieve the jobs you would:

$jobs = $candidate->availability->jobs->where('key_on_jobs_table', $value)->get();