Nested sequences in Premiere Pro are great for two reasons: they reduce timeline clutter by condensing multiple clips into one, and they allow you to combine effects such as Warp Stabilizer and Time Remapping. Jourdan Aldredge demonstrates both of these scenarios in this Premiumbeat blog post.
Nesting in Premiere Pro is a great tool for streamlining a long project. It’s also great for combining more effects to a clip than is usually possible. Here’s how to use it. —Jourdan Aldredge, Premiumbeat Blog