AGGREGATE in MDX

Your AGGREGATE(%TIMERANGE(...), Measures.Measure) pattern is the right general approach for a cumulative value over a time dimension, and it has been shown to work for running totals such as:

AGGREGATE(%TIMERANGE(YourTimeDimension.hierarchy.level,YourTimeDimension.hierarchy.level.CurrentMember),Measures.YourMeasure) [1]

A similar working example for cumulative totals is:

AGGREGATE(%TIMERANGE(DateOfSale.[Actual].[MonthSold].&,DateOfSale.CurrentMember), MEASURES.[Amount Sold])

used to return revenue from a starting month up to the current member on the rows axis. [3]

For your case, the likely issue is not the AGGREGATE syntax itself, because the sources show that AGGREGATE with %TIMERANGE works with ordinary measures like %COUNT and other standard measures. [1][3][4]

Your distinct-count measure is based on:

COUNT([dimension].[H1].[dimension].Members, EXCLUDEEMPTY)

and there is evidence that COUNT-based distinct member measures are a slower/special case, with InterSystems recommending the Distinct plug-in via %KPI() instead of using MDX COUNT for distinct member count. One reported solution says the provided Distinct plug-in is intended specifically to address the inefficiency of MDX COUNT distinct-member calculations. [5]

If you are counting distinct members, the documented alternative is to use the Distinct plug-in with %KPI() syntax rather than COUNT(...). The example syntax shown is:

%KPI("Custom DC Distinct","DISTINCT",1,"%level","<level spec>","%CONTEXT") [6]

and another source states that the built-in Distinct plug-in is the recommended approach for distinct member count instead of MDX COUNT. [5]

To troubleshoot the specific ERROR #5001: No member provider object found for member function: MEMBER(5) in your environment, the available guidance is to run the generated MDX in the DeepSee Shell and inspect the query/plan/trace there. The shell supports retrieving the last Analyzer query with #, showing the query plan with plan, and enabling trace with trace on. [7][8]

I do not see a source here that explains that exact #5001 error or proves exactly why your calculated measure fails inside AGGREGATE while %COUNT works. Based on the retrieved material, the safest guidance is:

1. Keep the cumulative pattern based on AGGREGATE(%TIMERANGE(...), measure) for running totals. [1][3]
2. Replace the distinct-count COUNT(...Members, EXCLUDEEMPTY) measure with a Distinct %KPI()-based measure if your goal is distinct member counting. [6][5]
3. Test the generated MDX in DeepSee Shell and inspect plan / trace to isolate whether the failure is in Analyzer-calculated-member evaluation. [7][8]

I do not have a source here that gives a direct fix for combining your exact COUNT(..., EXCLUDEEMPTY) calculated measure with AGGREGATE without error. [1][7][8][6][3][5]

Sources: