CxO is a short way to refer, collectively, to corporate executives at what is sometimes called the C-level , whose job titles typically start with "Chief" and end with "Officer." From what I gather from this definition, the "x" is to be replaced by the specific position in which this person is a chief officer; executive, financial...etc. So, in your context, I think it refers to all he corporate chief officers of different sections, in which case it is suitabe in my opinion to translate it to:
كبار موظفي الشركة
https://whatis.techtarget.com/definition/CxO

رئيس تنفيذي خبير وفي حالة الجمع رؤساء تنفيذيون خبراء