You can approach this request via workflow with 2 ways.

1. Action – Set Field Display Type ; Trigger – after field edit. Once one is checked disable the other.  Don’t forget to support the disable display action at before record load as well.
2. Action – Return User Error ; Trigger – after field edit ; condition check box A & B = True/checked.
3. Consider to change this 2 checkboxes to one custom list field. 

Indeed, both Full Licensed Users or Employee Center licenses requires that. The main difference is their functionality and  cost. Navigate to Setup > Company > View Billing Information > Billable Components tab to track your licenses.

Once customize your summary report , you will see tab named “More Options”.  At this tab you will see field named “Drill Down Report” where you can choose/link your customize detail report.

What is the type of the  entity custom field ?

Which trigger do you use at your Set Field Value action?

Do you enable the workflow logs?

You can achieve this request by adding a custom field at vendor entity that will use as indicator.

Then:

1. 1. Create saved search of vendors without this indicator and restrict it to any role/s you would like.
   2. Create a workflow that return user error for specific roles (before record load) once viewing/entering to a vendor with this indicator marked.

The answer for both questions is to add to the employee’s role the permission of: Publish Search.

Lists –> Publish Search. This permission allows usage and sharing of saved searches.

At first, validate that your “Execute As Admin”  checkbox is marked at the workflow.

Moreover, try to add the user’s role (i.e: employee center) to the workflow conditions.

Currently only via CSV import.

In the Results tab, add Formula (Text).

Enter the following formula in the Formula column: TO_CHAR({xxxx}, ‘YYYY-MM-DD HH:MM:SS’)

XXXX – field’s ID

Make sure that you have enabled the “Vendor Prepayments”  feature under Setup –> Enable Features –> Accounting subtab