Nested collections lambda iteration

Suppose I have an object containing a collection, each elements on the said collection contains a collection, and each collection contains a collection.

And I want to iterate on the deepest objects and apply the same code to it.

The imperative way is trivial, but is there a way to lambda-fy this all?

Here is how the code looks today:

My object o;
SecretType computedThingy = 78;
for (FirstLevelOfCollection coll : o.getList()) {
  for (SecondLevelOfCollection colColl : coll.getSet()) {
    for (MyCoolTinyObjects mcto : colColl.getFoo()) {
      mcto.setSecretValue(computedThingy);
    }
  }
}

I can see how to make a lambda out of the deepest loop:

colColl.getFoo().stream().forEach(x -> x.setSecretValue(computedThingy)

But can I do more?