📂 routes
- Rindex.tsx
- Rabout.tsx
- 📂 invoices
  - 📂 $invoiceId
    - 📂 activity
    - Lactivity.tsx
    - Rindex.tsx
    - Rdetails.tsx
  - L$invoiceId.tsx
  - Rindex.tsx
- Linvoices.tsx
- Rthis.works.tsx
- 📂 and.this.works
  - Rtoo.tsx
- Land.this.works.tsx
- 📂 __template-person-list
  - Rcustomers.tsx
  - Rvendors.tsx
- L__template-person-list.tsx
- 📂splat
- Lsplat.tsx
- 📂 posts
  - Rmarkdown.md
  - RMDX.mdx
- Lposts.tsx
- 📂 reports
  - R$date[.csv].ts
- 📂 some-list
  - Rgrid-view.tsx
  - Rlist-view.tsx
- Lsome-list.tsx
- 📂 errors
  - Rgood.tsx
  - Rbad.tsx
- Lerros.tsx

./routes/invoices.tsx

./routes/invoices/$invoiceId.tsx

./routes/invoices/$invoiceId/activity.tsx

./routes/invoices/$invoiceId/activity/$activityId.tsx

All these routes will be matched to the same hierarchy that ends with $activity.tsx

But not the following because $activity.tsx has siblings whose file names matches exaclty with the route leaf(all, latest).

You can access router parameters using "useParams". So in this page:

invoiceId is something

activityId is something-else