An update on this. I found a suitable parameter within the ContactPerson OVS --- RelationshipBusinessPartnerInternalID. This is, I believe, the ID of the company. SO when I tried to go into the ID-field configuration and add this field as a parameter and set it to the value of the company ID, it threw up an error message as below.
However, once I clicked through this it showed as being bound, as shown.
So one would think it'd only show entries where the RelationshipBusinessPartnerInternalID is the same as the company ID, right? But when I'm creating a new project, this happens...
As you can see, all of the contacts are shown, not just the ones for the chosen company. Is anyone able to explain why this isn't working, and how to remedy it? Thanks.