Feature request #16430
Expression Builder dialog should list the preset layers' visibilities
|Pull Request or Patch supplied:||No||Resolution:|
|Easy fix?:||No||Copied to github as #:||24339|
In the map composer item, you can lock layers in the map using preset visibility option. You can even "data-defined" its locked state (using presets or layer list).
However, in the data-defined button options, there's no way to easily find the layers' name (see #11680) nor the preset visibilities' name.