I have a simple view that shows documents at 4 different steps in a process wether 4 different fields are filled or not.One column shows an icon with this formula :
You might want to embedd the view in a form or page an look at the single
You might want to make this colum sortable (second tab in proberties) - which would group documents of the same time together
You could simply do 4 views
You could select via agent
If you have the option to do the data in nsfdb2 and to access via sql, that view could have a dialog to select this (have never doen this but seen demo, and the installation is quite something).