Hi Vicky,
BI/BO background is not required.
Since you have ABAP experience so it will be easier for you to grasp SQL concepts if you don't know them.
Well these books are sufficient but I would also suggest you to read HANA Modeling Guide and SQL Script Reference guides from the below link:
SAP HANA Platform – SAP Help Portal Page
Just go through these books thoroughly and perform hands on of all the exercises provided in these books.
In addition, you can also check my blog:
Prepare for SAP HANA Application Associate Certification
Regards,
Vivek