Your original [5% Members] aggregate calculation
gives different results depending on a view granularity.
When no other dimensions are on a view
(besides Measure Names),
then your [5% Members] gives 170.
When [Customer Name] dimension is on a view,
then your [5% Members] gives 0 (see Sheet 1),
and all subsequent calculations using [5% Members]
could not give the results anticipated.
To get it right one could calculate [5% Members]
at the level of details excluding [Customer Name].
Please find the attached wb w/mods.
Hope it could help.