diff --git a/packages/core/addon/utils/jexl.js b/packages/core/addon/utils/jexl.js
index 2117e9a9f..7016570cf 100644
--- a/packages/core/addon/utils/jexl.js
+++ b/packages/core/addon/utils/jexl.js
@@ -11,6 +11,14 @@ export const mapby = (arr, ...keys) => {
   );
 };
 
+export const flatten = (array) => {
+  if (!Array.isArray(array)) {
+    return null;
+  }
+
+  return array.flat();
+};
+
 /**
  * Transform a JEXL expression into it's AST
  *
diff --git a/packages/form/addon/lib/document.js b/packages/form/addon/lib/document.js
index 35eca2333..60c00c35a 100644
--- a/packages/form/addon/lib/document.js
+++ b/packages/form/addon/lib/document.js
@@ -5,7 +5,11 @@ import jexl from "jexl";
 import { cached } from "tracked-toolbox";
 
 import { decodeId } from "@projectcaluma/ember-core/helpers/decode-id";
-import { intersects, mapby } from "@projectcaluma/ember-core/utils/jexl";
+import {
+  intersects,
+  mapby,
+  flatten,
+} from "@projectcaluma/ember-core/utils/jexl";
 import Base from "@projectcaluma/ember-form/lib/base";
 
 const onlyNumbers = (nums) =>
@@ -180,6 +184,7 @@ export default class Document extends Base {
       return nums.length ? sum(nums) / nums.length : null;
     });
     documentJexl.addTransform("stringify", (input) => JSON.stringify(input));
+    documentJexl.addTransform("flatten", flatten);
 
     return documentJexl;
   }
diff --git a/packages/form/tests/unit/lib/document-test.js b/packages/form/tests/unit/lib/document-test.js
index 14f18bb90..5fe2f8963 100644
--- a/packages/form/tests/unit/lib/document-test.js
+++ b/packages/form/tests/unit/lib/document-test.js
@@ -235,7 +235,7 @@ module("Unit | Library | document", function (hooks) {
     );
   });
 
-  test("it stringifies correctly", async function (assert) {
+  test("it transforms correcty with stringify transform", async function (assert) {
     assert.true(
       await this.document.jexl.eval(
         '\'["test1","test2"]\' == value|stringify',
@@ -246,6 +246,21 @@ module("Unit | Library | document", function (hooks) {
     );
   });
 
+  test("it transforms correcty with flatten transform", async function (assert) {
+    const expression = "array|flatten";
+
+    assert.deepEqual(
+      await this.document.jexl.eval(expression, {
+        array: [["some-value"], ["some-other-value"]],
+      }),
+      ["some-value", "some-other-value"]
+    );
+    assert.strictEqual(
+      await this.document.jexl.eval(expression, { array: null }),
+      null
+    );
+  });
+
   test("computes the correct jexl context", async function (assert) {
     assert.expect(1);