So (for some reason), consultants are copy-monitoring elements that they should not be directly modifying based on their discipline, and now all of that needs to get hidden away? Ouch.
https://forum.dynamobim.com/t/copy-monitor-watched-elements/28660
This is a brief discussion that suggests that the copy-monitor association that we can very obviously see in the main Revit client isn't exposed to tap into with a Dynamo workflow. Unfortunate. So that leaves something like location-based association.
What this means is that you'd collect all of the elements of interest from the source linked file (VAVs from the Mechanical linked file, in this instance), collect all of the elements of interest from the other linked files, use GetLocation to simplify the comparison to points instead of solid geometry, then use DistanceTo, looking for zero or minimal distance groupings. This is probably going to be quite lag-intensive due to the number of comparisons, I honestly wouldn't recommend this route (what do you do when the model updates with more of these in the future?) In the case of 100 VAV boxes that's 100x100x(number of linked models) comparisons. You would also wind up missing any copy/monitored elements that have substantially moved between links.
Most quick-fix solutions will require consultant participation. Off-the-cuff, having consultants assign copy/monitored elements to a specific Workset would allow for view filtering.