This is an example of a custom item view that contains childViews.

CustomItemView.js

// Note: by mixing in SC.ContentDisplay, we get `content` added as a displayProperty
MyApp.CustomItemView = SC.View.extend(SC.ContentDisplay, {
  
  // ---------------------------------------------------------------------------
  // Properties
  //

  classNames: ['custom-item-view'],

  content: null,

  // When these properties change on the content, this view will redraw.
  contentDisplayProperties: ['username'],

  // When these properties change on the view, this view will redraw.
  // Note that SC.CollectionView sets several properties on each item, including: content, isEnabled, isSelected, contentIndex
  // @see http://docs.sproutcore.com/#doc=SC.CollectionView&method=exampleView&src=false
  displayProperties: ['isSelected'], // content is not required, it is in SC.ContentDisplay

  isSelected: false,
  
  // ---------------------------------------------------------------------------
  // Child Views
  //

  childViews: ['simpleChild', 'complexChild'],

  // A simple child view that doesn't care about the content.
  simpleChild: SC.ImageButtonView.extend({
    action: 'deleteItem',
    layout: { left: 8, centerY: 0, width: 30, height: 30 },
    image: 'delete-item-button'
  }),

  // A complex child that depends on the content of the parent. This is less that ideal, but with proper item pooling, shouldn't be an issue.
  complexChild: SC.View.extend({

    // This will be assigned across from the parent using Option 1 or Option 2 below. If the parent is going to be doing some
    // rendering, then I suspect Option 2 is better. If the parent is simply a container of other child views, then Option 1 may
    // be better (and *don't* have any displayProperties/contentDisplayProperties on the parent if it's not going to render anything).
    content: null,

    // Ensure that this view updates when content changes.
    displayProperties: ['content'], 

    layout: { left: 30, height: 100, right: 10, border: 1 },

    // Option 1. Bind content. Whenever the content of the parent is set, this view's content will change.
    contentBinding: SC.Binding.oneWay('.parentView.content'),

    render: function (context) {
      // Render our own whatever.
    },

    update: function (jqObject) {
      // Update our own whatever.
    }

  }),

  // ---------------------------------------------------------------------------
  // Methods
  //

  render: function (context) {
    var content = this.get('content'),
      isSelected = this.get('isSelected'),
      portionsOfContentForThisView = '';

    // Add a selected class.
    context.setClass({
      sel: isSelected
    });

    // Get the content properties that *this* view will render (not the complexChild).
    if (content) {
      portionsOfContentForThisView = content.get('something');
    }

    // Render this view's content (note that the simpleChild and complexChild will render after this).
    context = context.begin().addClass('custom-items-own-content');
    context.push(portionsOfContentForThisView);
    context = context.end();

    // etc.

    // Option 2. Don't bind the content up there. Set it across from down here.
    this.setPath('complexChild.content', content);
  },

  update: function (jqObject) {
    var content = this.get('content'),
      isSelected = this.get('isSelected'),
      portionsOfContentForThisView = '';

    // Update the selected class.
    jqObject.toggleClass('sel', isSelected);

    // Get the content properties that *this* view will update (not the complexChild).
    if (content) {
      portionsOfContentForThisView = content.get('something');
    }

    // Update this view's content (note that the simpleChild will *not* update, 
    // but the complexChild will update itself since content changes for it)
    jqObject.find('.custom-items-own-content').html(portionsOfContentForThisView);

    // etc.

    // Option 2 continued. Don't bind the content up there. Update it across from down here.
    this.setPath('complexChild.content', content);
  }
  
});