Test Tree UI doesn't consolidate common nodes

[blmille1]

I'm coming from Mocha Sidebar and we have tests spread out over many files that go under common, top-level labels.

For example, we have a top-level tree label called "Lambda." We put all of our AWS Lambda entry point tests under there.
In Mocha Sidebar, I see only one "Lambda" tree node at the top. Then, as I expand it out, it has other tree nodes (that may be consolidated from other files).
For example:

> Lambda
    > contentImport
       > should do this
       > should do that
    > contentExport
       > should do this
       > should do that

However, when I load the same mocha setup with this product, I see a bunch of Lambda top-level nodes, which expand out apparently based off what it found in that particular test file.
For example:

> Lambda
    > contentImport
       > should do this
> Lambda
    > contentImport
       > should do that
> Lambda
    > contentExport
       > should do this
       > should do that (when in the same file as the one above it)

How do we get the better tree behavior like we get from Mocha Sidebar but using this product instead?