<div data-type='project' id='example1'>
  <input name='start-date'/>
  <div data-type='project-lead' id='example2'>
    <input name='department'/>
    <input name='email'/>
    <div data-type='analyst'>
      <input name='department'/>
      <input name='email'/>
    </div>
    <div data-type='analyst'>
      <input name='department'/>
      <input name='email'/>
    </div>
    <div data-type='analyst'>
      <input name='department'/>
      <input name='email'/>
    </div>
  </div>
  <div class="JustToMakeMyLifeMoreDifficult">
    <div data-type='sponsor'>
      <input name='department'/>
      <input name='email'/>
    </div>
    <div data-type='sponsor'>
      <input name='department'/>
      <input name='email'/>
    </div>
  </div>
</div>

myData($obj){
  return $obj.find('[data-type]').not([data-type elements further down]);
}

myData($('#example1'))
myData($('#example2'))

[project-lead,sponsor,sponsor]
[analyst, analyst, analyst]

(function( $ ){
  $.fn.dataChildren = function(_selector) {
        var iter = this;
        var res = this.children(_selector);
        while ( ( iter = iter.children(':not(' + _selector +')') ).length ) {
                res = res.add(iter.children(_selector));
        }
        return res;
  };
})( jQuery );

$('#example1').dataChildren('[data-type]')

var el = $('#example1');

var res = el.children('[data-type]');

while ( ( el = el.children(':not([data-type])') ).length ) {
    res = res.add(el.children('[data-type]'));
}

var el = $('#example1');  // el is the current level
var res = $();            // res holds the result
var data_types;           // holds the children with data-type for the current level

do {
      // from current level, get children with data-type
    data_types = el.children('[data-type]');

      // add those to the result set
    res = res.add( data_types );

      // make the current level be the children of the current level that
      //      do NOT have data-type
    el = el.children().not( data_types );

} while( el.length ); // continue as long as the new current level
                      //     has at least one element

var ex = $('#example1');

var res = ex.find('> [data-type], > * > [data-type]');

var ex = $('#example1');

var res = ex.find('> [data-type], > :not([data-type]) > [data-type]');

'> [data-type]'

'> :not([data-type]) > [data-type]'

function getNodes(id) {
  var el = (typeof id == 'string')? document.getElementById(id) : id;
  var result = [];
  var node, nodes = el.childNodes;
  var prop = 'data-type';
  var tag = 'div';

  for (var i=0, iLen=nodes.length; i<iLen; i++) {
    node = nodes[i];

    if (node.tagName && node.tagName.toLowerCase() == tag) {

      if (node.getAttribute(prop)) {
        result.push(node);

      } else {
        result = result.concat(getNodes(node));
      }
    }
  }
  return result;
}

$obj.find('> [data-type]');