Need a simply module to learn 'fog of war'

Hi all,
in my module (under construction), I have a map and 2 sigle pieces P1 & P2 in my [Game piece palette].
Each [single piece] have a [Property Sheet] called with a menu xxxx (CTRL+A).
I set 2 [Definition of Player Sides] : SIDE1, SIDE2.

My need :

if I play SIDE1 :

  • I can see P1 and his [Property Sheet]. I can modify the [Property Sheet].
  • I can see P2 but not his [Property Sheet]. I can’t modify the [Property Sheet].
    I can move P1 and P2 on the map.

on the other hand, if I play SIDE2 :

  • I can see P1 but not his [Property Sheet]. I can’t modify the [Property Sheet].
  • I can see P2 and his [Property Sheet]. I can modify the [Property Sheet].
    I can move P1 and P2 on the map.

Thank you for help !

That’s OK, i find the [Restricted Access] !
But, now, how a NEUTRAL single piece could change to SIDE1 or SIDE2 (mercenaries for example) ?
How can I associate a “Player Side” with a [Global Property] ? >> if I switch a this global property, the side change for this piece… How can I manage that ?