Use the dimension tag Cb# in the POV for the cube view intersections. However, the Cube View editor doesn't recognize Cb# as a valid dimension tag (at least for my OS version 6.4) so I use an XFBR rule to generate Cb#Cube2.
In my example below, Column1 pulls data from P1Main cube. Column 2 pulls data from a 2nd cube called P1EmployeePlan where the XFBR call returns Cb#P1EmployeePlan from my function ST_ParamHelper>GetCubeMbrString.
The 2nd screenshot shows the GetCubeMemberString function that simply returns Cb#param value.
The 3rd screenshot shows that both columns are pointing to different cubes.
Hopefully, OneStream will eventually introduce Cb# in Cube View editor Member Filter Builder interface!