I have experienced working in both corporate development department and accounting department.
この場合、次のような言い方ができますよ。
ーI have experience working in both corporate development and accounting departments.
「私は経営企画部と経理部の両方で働いた経験があります」
corporate development department「経営企画部」
accounting department「経理部」
例:
I worked at my former company for ten years, six years in the corporate development department and four years in the accounting department.
「前の会社で10年働き、6年は経営企画部、4年は経理部で働いた」
ご参考まで!