Does it have the CMakeLists.txt you expect for your ESP-IDF project? Does it build using pio run?
You might be running in an error already discussed in the forums (Newly generated espidf project doesn't build in CLion - #15 by valeros), that using ESP-IDF, which is CMake based, does not play well with CLion which is also CMake based. The CMakeLists.txt of the project needed for ESP-IDF is overwritten by PIO when it reinits the project for CLion.