Create 1st PPV as a global PPV (need to make it as a main PPV, precedence), in Details:
set Priority as 1,
In Exposue setting, Metering mode: Manual
Drag 2nd PPV as an exterior PPV
Set Infinite Extent to True (allow to see its effect everywhere in scene)
Priority as 0
this time set Metering mode to Auto Exposure Historgram,
then enable Exposure Compensation (play around the value for exposure)
Also in Local Exposure, enable Contrast Expousre (to play around contrast)
To move the PPV to other Map:
Open Level in Top Window Menu → Select the PPV in outliner
→ Create New in Level:
Choose save level as wanted (a PPV Level will be created)
To let the effect see in play mode:
R click the PPV in level → Light Scenario → Change Streaming Method →Always loaded