View filter by nid via relationships
Please take a look at the views export below, this will give you user values. This will work on editing the task but not when you are initially creating the task (as the field_parent_project does not yet have a value stored against it).

$view = new view();
$view-&gt;name = 'test';
$view-&gt;description = '';
$view-&gt;tag = 'default';
$view-&gt;base_table = 'users';
$view-&gt;human_name = 'Test';
$view-&gt;core = 7;
$view-&gt;api_version = '3.0';
$view-&gt;disabled = FALSE; /* Edit this to true to make a default view disabled initially */

/* Display: Master */
$handler = $view-&gt;new_display('default', 'Master', 'default');
$handler-&gt;display-&gt;display_options['title'] = 'Test';
$handler-&gt;display-&gt;display_options['use_more_always'] = FALSE;
$handler-&gt;display-&gt;display_options['access']['type'] = 'perm';
$handler-&gt;display-&gt;display_options['access']['perm'] = 'access user profiles';
$handler-&gt;display-&gt;display_options['cache']['type'] = 'none';
$handler-&gt;display-&gt;display_options['query']['type'] = 'views_query';
$handler-&gt;display-&gt;display_options['exposed_form']['type'] = 'basic';
$handler-&gt;display-&gt;display_options['pager']['type'] = 'full';
$handler-&gt;display-&gt;display_options['pager']['options']['items_per_page'] = '10';
$handler-&gt;display-&gt;display_options['style_plugin'] = 'default';
$handler-&gt;display-&gt;display_options['row_plugin'] = 'fields';
/* Relationship: Entity Reference: Referencing entity */
$handler-&gt;display-&gt;display_options['relationships']['reverse_field_project_team_node']['id'] = 'reverse_field_project_team_node';
$handler-&gt;display-&gt;display_options['relationships']['reverse_field_project_team_node']['table'] = 'users';
$handler-&gt;display-&gt;display_options['relationships']['reverse_field_project_team_node']['field'] = 'reverse_field_project_team_node';
/* Relationship: Entity Reference: Referencing entity */
$handler-&gt;display-&gt;display_options['relationships']['reverse_field_parent_project_node']['id'] = 'reverse_field_parent_project_node';
$handler-&gt;display-&gt;display_options['relationships']['reverse_field_parent_project_node']['table'] = 'node';
$handler-&gt;display-&gt;display_options['relationships']['reverse_field_parent_project_node']['field'] = 'reverse_field_parent_project_node';
$handler-&gt;display-&gt;display_options['relationships']['reverse_field_parent_project_node']['relationship'] = 'reverse_field_project_team_node';
/* Field: User: Name */
$handler-&gt;display-&gt;display_options['fields']['name']['id'] = 'name';
$handler-&gt;display-&gt;display_options['fields']['name']['table'] = 'users';
$handler-&gt;display-&gt;display_options['fields']['name']['field'] = 'name';
$handler-&gt;display-&gt;display_options['fields']['name']['label'] = '';
$handler-&gt;display-&gt;display_options['fields']['name']['alter']['word_boundary'] = FALSE;
$handler-&gt;display-&gt;display_options['fields']['name']['alter']['ellipsis'] = FALSE;
/* Sort criterion: User: Created date */
$handler-&gt;display-&gt;display_options['sorts']['created']['id'] = 'created';
$handler-&gt;display-&gt;display_options['sorts']['created']['table'] = 'users';
$handler-&gt;display-&gt;display_options['sorts']['created']['field'] = 'created';
$handler-&gt;display-&gt;display_options['sorts']['created']['order'] = 'DESC';
/* Contextual filter: Content: Nid */
$handler-&gt;display-&gt;display_options['arguments']['nid']['id'] = 'nid';
$handler-&gt;display-&gt;display_options['arguments']['nid']['table'] = 'node';
$handler-&gt;display-&gt;display_options['arguments']['nid']['field'] = 'nid';
$handler-&gt;display-&gt;display_options['arguments']['nid']['relationship'] = 'reverse_field_parent_project_node';
$handler-&gt;display-&gt;display_options['arguments']['nid']['default_action'] = 'default';
$handler-&gt;display-&gt;display_options['arguments']['nid']['default_argument_type'] = 'node';
$handler-&gt;display-&gt;display_options['arguments']['nid']['summary']['number_of_records'] = '0';
$handler-&gt;display-&gt;display_options['arguments']['nid']['summary']['format'] = 'default_summary';
$handler-&gt;display-&gt;display_options['arguments']['nid']['summary_options']['items_per_page'] = '25';
/* Filter criterion: User: Active */
$handler-&gt;display-&gt;display_options['filters']['status']['id'] = 'status';
$handler-&gt;display-&gt;display_options['filters']['status']['table'] = 'users';
$handler-&gt;display-&gt;display_options['filters']['status']['field'] = 'status';
$handler-&gt;display-&gt;display_options['filters']['status']['value'] = '1';
$handler-&gt;display-&gt;display_options['filters']['status']['group'] = 1;
$handler-&gt;display-&gt;display_options['filters']['status']['expose']['operator'] = FALSE;

/* Display: Entity Reference */
$handler = $view-&gt;new_display('entityreference', 'Entity Reference', 'entityreference_1');
$handler-&gt;display-&gt;display_options['defaults']['title'] = FALSE;
$handler-&gt;display-&gt;display_options['pager']['type'] = 'some';
$handler-&gt;display-&gt;display_options['defaults']['style_plugin'] = FALSE;
$handler-&gt;display-&gt;display_options['style_plugin'] = 'entityreference_style';
$handler-&gt;display-&gt;display_options['style_options']['search_fields'] = array(
  'name' =&gt; 'name',
);
$handler-&gt;display-&gt;display_options['defaults']['style_options'] = FALSE;
$handler-&gt;display-&gt;display_options['defaults']['row_plugin'] = FALSE;
$handler-&gt;display-&gt;display_options['row_plugin'] = 'entityreference_fields';
$handler-&gt;display-&gt;display_options['defaults']['row_options'] = FALSE;