I think you missed the point, let me explain:
say you have 3 folders, the first 2 are somewhat secret and the 3rd is very secret.
So you create two folder sets, in the first you add the first 2 folders and in the second you add the 3rd.
Now if you enter the password for first folder set only the 2 folders will show up in Espionage, if you lock it and enter the password for second folder set then only the 3rd folder will show up.
The idea behind is that you get somebody forcing you to unlock your protected data, you can choose which password you will enter and there is no way the intruder can know if you have multiple passwords i.e folder sets. So you reveal only the less secret data.
But maybe I did not understand what is bothering you, so if it is me who missed the point, please correct me.
Thanks
Zsolt