Multiple Testfiles in PyCharm

I've written multiple test-files for a PyCharm-Project and want to run them all together like in IntelliJ. But it seems to be not that easy as in IntelliJ, because in IntelliJ I can mark all testfiles I want to run, click right and select "Run tests". In PyCharm I cannot do that and when I want to create a unittest, I can only select one testfile, same for pytest.