How to create pr per solution not per project

[Maggus85]

I have a .net solution with structure

solution.sln

Api.csproj
Aplication.csproj
Infrasctructure.csproj
Each project have some public and private nuget dependencies, I would like to create two pr for this solution

first - with public dependencies
second - with private dependencies

Currently with grouping option I'm only able to create those pr per project not per solution, so in effect I have

pr for Apiwith public dependencies
pr for Api with private dependendencies
pr for Aplication with public dependencies
pr for Aplication with private dependendencies
pr for Infrasctructure with public dependencies
pr for Infrasctructure with private dependendencies

I'm using configuration, is there any option to crete only two pr per solution, like described?

`version: 2
registries:
farm-cloud:
type: nuget-feed
url: https://agrisolutionseu.pkgs.visualstudio.com/_packaging/FarmCloud/nuget/v3/index.json
token: PAT:${{VSS_NUGET_ACCESSTOKEN}}
nuget:
type: nuget-feed
url: https://api.nuget.org/v3/index.json
schedule:
interval: "daily"
updates:

package-ecosystem: "nuget"
directory:
/src/API/AS.FarmCloud.Sensor.Storage/
open-pull-requests-limit: 20
registries:
farm-cloud
nuget
groups:
internal-libs:
applies-to: version-updates
patterns:
AS*`