Andrew Scheps walks through his template parallel vocal chain, a 90s East Coast pop technique he still uses today. Strip the low end, boost around 8 kHz, then hit an LA-2A, so the detector only responds to upper midrange and above.
This is conceptually similar to using a sidechain filter on a compressor's detector circuit, but the coloration of the EQ naturally produces a different result. It also works with any compressor, hardware or software, even ones without sidechain inputs or filter options.
After the compressor, low end is restored and a Pultec-style EQ adds a shelf at 20 kHz. That high-frequency choice came from trial and error with Pultec frequency interaction, not a strict technical decision.
The whole processed signal blends in parallel at a low level, making the vocal easier to hear without touching the fader or changing its tone.