ournal Entry Transaction with respect to segmentation accounts

Dear Friends,

I need some clarification regarding transaction of Journal entry based on segment cart of accounts.

For example

I have Account segmentation such as

Natural Account

Company

Region

Departments.

Now if i want a salary account transaction for departments then should i define salary accounts for each department or is it possible to select my departments at time of passing journal entry.

Regards:

Balaji.S