You want it such that certain customers can only be selected, when the site that Order Entry was launched from, is allowed for that customer. Correct?
Example:
- 4 Sites: A, B, C, D
- Cust ZYX Corp can only have orders placed from site B
If Order Entry is launched from site A, C or D, then Cust ZYX Corp can not be selected as the customer.
You could probably do something similar to the methods used in this thread about limiting records of related lists:
Your Customer table would need a field to hold the plant ID’s of the allowed sites. That could be used to limit search results from showing the customer, but wouldn’t prevent a user from manually entering it.
Another BPM could check that UD field against the current site, and prevent any updates if not allowed. This would prevent user from manually entering it.
You’d need to be very with that second BPM, as other processes may call the SaleOrder BO’s, from other sites. For example: You’d still want to be able to enter the AR Invoice in Site A, for the order that is restricted to site B