Nested Collections hierarchy visibility is wrong.

**EDIT:** rollback to version `3.6.1` and every goes back to normal. And here I thought I was doing something wrong ._.

**Describe the bug**
Nested Collections hierarchy visibility is wrong.

**To Reproduce**

Situation 1: Create the following filesystem structure:
```txt
src/
|-- index.md
|-- abc/
|-- index.md
```

Situation 2: Create the following filesystem structure:
```txt
src/
|-- index.md
|-- abc/
|-- index.md
|-- def/
|-- index.md
```

**Screenshots**

Situation 1: `Tests` collection focused, no `abc` nested collection.


Situation 2: `Tests` collection focused


`abc` collection focused, no `def` nested collection.


**Expected behavior**

1. `abc` nested collection should be visibled
2. `abc`/`def` nested collection should be visibled

**Applicable Versions:**

- Decap CMS version: 3.7.1
- Git provider: GitHub, Decap Server
- OS: Fedora KDE 41
- Browser version: LibreWolf, 139.0.4-1

- Node.JS version: none, use CDN

**CMS configuration**

```yml
# ...

collections:
- label: Tests
label_singular: test
name: tests
description: Nested Collections test
folder: "src/tests"
create: true
slug: "{{slug}}"
nested:
depth: 3
summary: "{{slug}}"
summary: "{{dirname}}/{{filename}}.{{extension}}"
extension: md
format: frontmatter
fields:
- { label: "Title", name: "title", widget: "string" }
meta: { path: { widget: string, label: 'Path', index_file: 'index' } }

# ...
```

**Additional context**