diff --git a/src/Filter.cpp b/src/Filter.cpp
index f6d0529ac..d98f9f576 100644
--- a/src/Filter.cpp
+++ b/src/Filter.cpp
@@ -35,6 +35,23 @@
 
 extern Context context;
 
+////////////////////////////////////////////////////////////////////////////////
+// Const iterator that can be derefenced into a Task by domSource.
+static std::vector <Task>::const_iterator contextTask;
+
+////////////////////////////////////////////////////////////////////////////////
+static bool domSource (const std::string& identifier, Variant& value)
+{
+  std::string stringValue = context.dom.get (identifier, *contextTask);
+  if (stringValue != identifier)
+  {
+    value = Variant (stringValue);
+    return true;
+  }
+
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 Filter::Filter ()
 : _startCount (0)
@@ -72,7 +89,7 @@ void Filter::subset (const std::vector <Task>& input, std::vector <Task>& output
 
     Eval eval;
     eval.addSource (namedDates);
-    // TODO Need DOM source.
+    eval.addSource (domSource);
     eval.compileExpression (filterExpr);
 
     std::vector <Task>::const_iterator task;
@@ -82,6 +99,8 @@ void Filter::subset (const std::vector <Task>& input, std::vector <Task>& output
       if (oldFilter)
         output.push_back (*task);
 
+      contextTask = task;
+
       Variant var;
       eval.evaluateCompiledExpression (var);
 
@@ -122,7 +141,7 @@ void Filter::subset (std::vector <Task>& output)
 
     Eval eval;
     eval.addSource (namedDates);
-    // TODO Need DOM source.
+    eval.addSource (domSource);
     eval.compileExpression (filterExpr);
 
     output.clear ();
@@ -134,6 +153,8 @@ void Filter::subset (std::vector <Task>& output)
       if (oldFilter)
         output.push_back (*task);
 
+      contextTask = task;
+
       Variant var;
       eval.evaluateCompiledExpression (var);
 
@@ -153,6 +174,8 @@ void Filter::subset (std::vector <Task>& output)
         if (oldFilter)
           output.push_back (*task);
 
+        contextTask = task;
+
         Variant var;
         eval.evaluateCompiledExpression (var);