Only show heritage in Belgium

Because the choices are Belgium-specific

assets/layers/tree_node/tree_node.json

@@ -330,12 +330,16 @@
           "hideInAnswer": true
         }
       ],
-      "condition": {
+      "condition": { "or": [
-        "or": [
+        "heritage~*",
-          "denotation=landmark",
+        { "and": [
-          "denotation=natural_monument"
+          "_country=be",
-        ]
+          { "or": [
-      }
+            "denotation=landmark",
+            "denotation=natural_monument"
+          ]}
+        ]}
+      ]}
     },
     {
       "render": {