How long can I stay in my home country on an approved Advance Parole?

No limit but be sure someone is monitoring your U.S. I-485.

While an advance parole ensures that you will be readmitted, it is not advisable to stay out for an extended period as CBP is going to be tougher on admitting foreign nationals so you need to verify you plan to return soon and that you have a valid reason to be abroad for an extended period.

An approved Advance Parole document allows you to travel outside the U.S. and return without abandoning your pending I-485 application. Key points to
consider:
Validity: Return before your Advance Parole expires. Yours is valid until 2029.
Extended Stay: No specific time limit, but long stays may raise questions about your intent to reside in the U.S., potentially affecting your application.
Reentry: You will be inspected by CBP upon return. Be prepared to explain your extended stay and intent to maintain U.S. residence.
Continuous Residence: Ensure your stay abroad does not affect any continuous residence requirements for your application.

You can return to the U.S. as long as your advance parole remains valid and AOS is pending. A travel for few months should cause any issues.