How to condition SelectQuery by field value?
Yay, I dit it:

$query = $view-&gt;build_info['query'];
$query-&gt;leftJoin(
  'field_data_field_referenced_user', 
  'field_referenced_user',
  'taxonomy_term_data.tid = field_referenced_user.entity_id'
);
$query-&gt;where(
  'field_referenced_user.field_referenced_user_target_id = :uid',
  array(':uid' =&gt; $user-&gt;uid)
);

$view-&gt;build_info['query'] = $query;