Request Set-Default operating unit

We have defined a request set

This request set is attached to a custom responsibility with MO:Operating Unit profile as X and MO:Security profile as Z

When we try to submit the request set from custom responsibility the operating unit field is automatically populated with Operating unit W (instead of X or z)

We are able to change the OU as required but the issue arises when PRC:Create Accounting needs to be run and we need to run it for all the operating units

Questions

1. From where is the default value in the operating unit field derived from?