I am pretty sure the following will work. For testing purposes you might want to test using just a few contacts then apply to all if it is working as you desire. I'm assuming you are using Contacts on the Mac but other programs probably have similar functionality.
1. From Contacts on the Mac create a new Smart Group choose
File>New Smart Group. In the sheet that appears name the Smart Group something appropriate such as Smaccomb's Work.
2. In the remainder of the sheet we are going to create a rule or series of rules based on something your work contacts have in common but different from family and others. Use the drop downs to set the rule to something like
Note contains smaccomb's work. Close the sheet.
3. Go to the card for one of your co-workers. Make sure the Notes field is showing and enter smaccomb's work or whatever you entered as the contains field for the rule. Make sure it is entered exactly the same way.
4. On her devices go to Contacts and deselect the groups that are not supposed to be seen.
If this is working as desired you'll have to add your phrase to the notes field of all your work contacts. You'll do that only once.
I used a Smart Group because it Auto Updates. The next time you add a work contact simply include the appropriate message in the Notes field and that person is added to the group automatically.
Just in case you need to add a field to the existing cards see
Contacts: Adding Fields & Changing the Card Template - The Mac Observer
You could also generate this rule based on any consistent characteristic as long as you change the rule accordingly and enter the information in the appropriate field.
