Hi everyone
We have a lookup column called Division setup in the Opportunity table::

This lookup column points to the Business Unit (BU) table:

We now have a requirement where one of the BUs should no longer be used when creating new opportunities. I don't want to delete the BU so thought I could hide this BU from the lookup column when a new form is opened for an opportunity. However, I'm not sure how I hide values from a lookup column, is it possible along the same lines as hiding values form choice columns?
Thanks in advance for any help you could give.