How to Validate and fetch Data from Multiple BOs

Summary:

We have a requirement where we need to validate the Id entered in an Text Box in Page1 based on the data stored in the 1st BO. We are validating this id using page module Rest call function.

Once the Id entered is valid, We have another field named Employee Benefits in the same first BO, we have a 2nd BO which stores the Employee Benefits with its Description and the Benefit Code.

There is also a 3rd BO which stores the Forms Related Details to the Employee Benefits of the 2nd BO.

When the Id is entered in Page 1. It is validated against the first BO. Once the Id is valid in Page 1,