Hi Sambath, have a look at our PER FAQs on the website. If you are using previous experience then the person who supervised your work at that time must be able to review and sign-off your experience.
There seems to be some relevant info to help answer your queries, which I've included below:
Yes. You can use experience from previous job roles (before or after registering as an ACCA student) to help you claim a performance objective. There is no specific time limit.
However, the qualified person who supervised your work at that time must be able to review and sign-off the performance objectives and time you claim on the basis of this experience.
Also, as the profession continually evolves, consider carefully if experience gained more than five years ago is still relevant.
No. You do not have to obtain your practical experience in an organisation which has been approved by ACCA. Although there are advantages to achieving your PER if you do work for an ACCA Approved Employer.
Hope this helps :)