By assigning cubes for Account, Entity, and Period members, you set to which cubes the members’ children have access. For example, Total Sales Account may be valid for Revenue and P&L, but Fixed Assets Account may be valid for only Balance Sheet. Not assigning a cube to a member prevents that member’s children from accessing that cube.
When moving members, if the new parent is valid for different cubes, members remain valid only for cubes they have in common with the new parent. If the new parent of an account member has another source cube, the member’s source cube is set to the first new valid cube of that member.