Yes it's possible.
For the MFG group, do not give them read permissions for the Pending ECO state.
Deselect show working versions of files for MFG.
Try that. Search for a file like you've describe and you'll see the don't have the latest version, and when they try to "get the lastest version" it doesn't change what they are looking at.
***Make sure your search form has "search in all versions" selected.
I would also suggest putting a "state" watermark on the drawing.
This does not appear to be correct or not working.
I have tested by removing read permission from users when file is at Pending ECO state.
Without NO read permission, when user searches for file which is in Pending ECO state no results show. File searched on is not visible at all.
I ensured show working versions was deslected and search in all versions was selected. No difference regardless.
Thus it appears if file is in Pending ECO state and permissions set to NOT READ in Pending ECO state, there is no visibility of file in that state, including previous versions and states.
Any other suggestions or expalnations?
Also, I am working with EPDM 2008.
Can you browse to it manually and see it?
I've noticed on the search, if the "Search Previous Versions" isn't set to be checked, then the search turns up no results for people who can only see a certain state but not others.
Corey had some great suggestions, so I would go through those also. However, deselecting the show working versions for that group should definitely do what you are looking for. I would suggest opening that user in the Administration tool and making sure that they do not have that option checked in all of the necessary folders. Then I would see what other groups they are in and make sure that those additional groups do not have that option set. 75% of the time when a permission isn't doing what it's supposed to is because it is enabled somewhere else.
Folder Settings for CAD folder for the "control group"
State Settings for "WIP" State - your ECO Pending State
Search results, first as admin to see latest. Notice state, and REV X01+ (newer than x01, under revision)
Then search as control group, without search in all versions checked, comes back blank.
Then with all versions selected, resultes, but not the "latest" version. Just the latest version they have access to.
I assume your Group has Read permission on some Previous state, and that the file has been in some state that they have access to?