Child route is incorrectly intercepted by adjacent route

[jacoblapworth]

Link to the code that reproduces this issue

https://codesandbox.io/p/devbox/quirky-hugle-9j7ns4

To Reproduce

1. Create dynamic routes inside adjacent parent routes

intercepter
↳ [id]
list
↳ [id]

2. Create a parallel intercepted route in one of the dynamic routes

intercepter
↳ [id]
    @modal
    ↳ (.)[id]

3. Soft navigate to the non-intercepted url /list/[id]

Current vs. Expected behavior

Id param on /list/[id] shows as "(.)id" e.g. for route /list/1 param id = "(.)1"

(.) Should only match on the same level, but instead seems to be matching one level up

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.4.0: Wed Mar 19 21:16:34 PDT 2025; root:xnu-11417.101.15~1/RELEASE_ARM64_T6000
  Available memory (MB): 32768
  Available CPU cores: 10
Binaries:
  Node: 22.14.0
  npm: 11.3.0
  Yarn: 1.22.19
  pnpm: N/A
Relevant Packages:
  next: 15.3.1-canary.11 // Latest available version is detected (15.3.1-canary.11).
  eslint-config-next: 14.2.15
  react: 19.1.0
  react-dom: 19.1.0
  typescript: 5.8.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Parallel & Intercepting Routes

Which stage(s) are affected? (Select all that apply)

next dev (local), next start (local), Vercel (Deployed)

Additional context

No response