diff --git a/src/notification/notification.service.ts b/src/notification/notification.service.ts
index a1d80e6..dcb5b82 100644
--- a/src/notification/notification.service.ts
+++ b/src/notification/notification.service.ts
@@ -112,6 +112,13 @@ export async function listNotifications(
   const sortObj = getSortObject(params, notificationFields);
   const filterObj = getFilterObject(params) || [];
 
+  filterObj.forEach((item) => {
+    if (item.changes) {
+      item[`changes.${item.changes.$eq}`] = { $exists: true };
+      delete item["changes"];
+    }
+  });
+
   if (user.role == "client") {
     filterObj.push({ client: new mongoose.Types.ObjectId(user.orgId) });
   }
diff --git a/src/unique.ts b/src/unique.ts
index a06bd11..b6f139c 100644
--- a/src/unique.ts
+++ b/src/unique.ts
@@ -37,6 +37,16 @@ export async function getUniqueFields(
   const model = modelMap[collection];
   if (!model) throw new Error("invalid collection");
 
+  if (collection === "notifications" && field === "changes") {
+    const changeKeys = await model.aggregate([
+      { $project: { changesKeys: { $objectToArray: "$changes" } } },
+      { $unwind: "$changesKeys" },
+      { $group: { _id: "$changesKeys.k" } },
+    ]);
+
+    return changeKeys.map((item) => item._id);
+  }
+
   let values = await model.distinct(field, { tenantId: user.tenantId });
 
   let matchedValues = [];