Setup

Download and install JetBrains CLion.

Create a new project and select “C++ Executable”. Use C++ 20 as the language standard.

Project Structure 

  <00-solution>/
├── <00-project1>/
│   ├── CMakeLists.txt
│   └── main.cpp
├── <00-prject2>/
│   ├── CMakeLists.txt
│   └── main.cpp
└── CMakeLists.txt

Solution CMakeLists.txt 

  cmake_minimum_required(VERSION 3.26)
project(00_solution)

set(CMAKE_CXX_STANDARD 20)

add_subdirectory("${PROJECT_SOURCE_DIR}/00-project1")
add_subdirectory("${PROJECT_SOURCE_DIR}/00-project2")

Project CMakeLists.txt 

  cmake_minimum_required(VERSION 3.26)
project(00_project1)

set(CMAKE_CXX_STANDARD 20)

add_executable(00_project1 main.cpp)