How to display object of objects in angular 7?

Question

Angular

There is an object of objects.

var rielt: Object = { 
  buy: {
    name: 'Купить',
    type: {
      name: 'somename',
      thing: {
        room: 'Комната',
        home:'Квартира'
      }
    }
  }, 
  rent: {
    name: 'Арендовать',
    type: {
      name: 'somename',
      thing: {
        room: 'Дом',
        home:'Замлю'
      }
    }
  }
};

I need to output something like this:

<mat-option value="buy">Купить</mat-option>
<mat-option value="rent">Арендовать</mat-option>

Next, set the conditions so that if you select the "Buy" option, then display the options in the adjacent select

<mat-option value="room">Комната'</mat-option>
<mat-option value="home">Квартира</mat-option>

Any ideas how to implement this?

Answer 1

For example