So it all depends on the business requirements. You have really asked an open ended question.

First of all, the source and target notion in the elimination set has nothing to do with subsidiary company and parent company.

Source means, from which accounts balances will be picked up for eliminations, and Target means in which account they will be closed in.

You can choose various ways of doing it.

Option 1:

You can say you will only eliminate balances from certain natural accounts.

In source you can enter:

-189100- (lets say this is your intercompany account)

In target you can enter:

E1-- (lets say this is your elimination company).

Option 2:

You can say you will eliminate balances from any natural accounts where there is certain value in intercompany segment

In source you can enter:

01--02 (trades between company 01 and 02)

In target you can enter:

E1-- (lets say this is your elimination company).

Option 3:

You can specify all segment values in your source accounts.