You are trying to filter by ETC or Allocation (or other attribute in the per-period metrics section) but the results you obtain are not the expected ones.
Clarity 16.3.2
The attributes in the per-period metrics section follow the "View Options" configuration (such as Periods, Type, Start Period, End Period and Totals).
The values for the attributes will be either the sum of the values in the displayed periods (when Totals setting is set to Sum of Periods) or the total value for all periods, displayed or not (when Totals setting is set to Grand Totals).
The values considered can be checked in the left hand side of the portlet when the corresponding Columns are displayed.