Struggling with creating deep nested hash

[rohandey]

I am struggling with this for couple of days, not able to form the desired deep nested hash, hope to get some help.
Input hash:

@data = { 'nodes' => { 
                'a' => {
                  'id' => 'a',
                  'parent_id' => 'root',
                  'children' => {
                    'a1' => {
                      'id' => 'a1',
                      'parent_id' => 'a',
                      'children' => { }
                    }
                  }
                },

                'b' => {
                  'id' => 'b',
                  'parent_id' => 'a',
                  'children' => {}
                },

                'c' => {
                  'id' => 'c',
                  'parent_id' => 'b',
                  'children' => {}
                },

                'b2' => {
                  'id' => 'b2',
                  'parent_id' => 'b',
                  'children' => {}
                }

              }}

Desired result:

@h = [{ 'nodes' => { 
                'a' => {
                  'id' => 'a',
                  'parent_id' => 'root',
                  'children' => {
                    'a1' => {
                      'id' => 'a1',
                      'parent_id' => 'a',
                      'children' => {}
                    },
                    'b' => {
                      'id' => 'b',
                      'parent_id' => 'a',
                      'children' => {
                        'c' => {
                          'id' => 'c',
                          'parent_id' => 'b',
                          'children' => {}
                        },

                        'b2' => {
                          'id' => 'b2',
                          'parent_id' => 'b',
                          'children' => {}
                        }
                      }
                    }
                  }
                }
              }}]    
      

What I am trying is this

@data['nodes'].each do |key, value| 
      if key == 'a'
        @h[0] = { 'a' => value }
      else 
        parent_key = value['parent_id']
        key_scope = Xf.scope(parent_key)
        
       @h.map(&key_scope.set! do |h, k, v| 
          if v.present?
            v['children'].update({ key => value })
          end
        end)
      end
    end 

Input @DaTa['nodes'] can have over 1000 elements and output can get nested to level n

Any help will be greatly appreciated.