Yes. Lightroom presets are stored as preset files, and you can inspect them directly.

In Lightroom, either:

• open Preferences > Presets and click Show Lightroom Presets Folder, then go to Develop Presets, or
• right-click the preset and choose Show in Explorer/Finder (if available).

Then open the preset file in a plain text editor such as Notepad or any code/text editor. In older Lightroom versions, these are typically .lrtemplate files. The file lists the parameters and values used by the preset, so you can see which adjustments it applies.

You can also edit the file manually or use it as the basis for a new preset, but make a backup first in case you want to restore the original.