MDX - filter by [Day] but display category of [Month] - mdx

Question

I’m hoping someone can help me out with restructuring/rewriting my MDX query – I’m fairly new to MDX and only know enough to be dangerous. I am using Mondrian if that makes a difference.
Here is the stacked bar chart I am producing…
Injuries by Month and Category
And here is my query (simplified to remove all the stuff not relevant to this question)…
WITH
SET [Date Range] AS {${mdxStartDateParam}.Parent : ${mdxEndDateParam}.Parent}
MEMBER [Measures].[Month Name] as [Incident Date.YQMD].currentmember.parent.parent.name || "-" || [Incident Date.YQMD].currentmember.name
SET [Classification Month Set] AS (
Hierarchize(
ORDER(
Hierarchize(FILTER([Classification].[Classification].members,[Classification].CURRENTMEMBER IN {Descendants([Classification].[${paramInjClass}])})),
[Measures].[Injury Count],
BDESC
)
) * [Date Range]
)
SELECT {[Measures].[Injury Count], [Measures].[Month Name]} ON COLUMNS,
NON EMPTY [Classification Month Set] ON ROWS
FROM [Injury Analysis]
The problem I have is that my two date parameters (${mdxStartDateParam} and ${mdxEndDateParam}) can be any date at the [Day] level, while my chart X Axis is showing at the [Month] level, and even if the ${mdxStartDateParam} is midway through a month my query is returning all data for the month.
eg. If I have an Injury that occurred on February 2nd but my ${mdxStartDateParam} is [Incident Date.YQMD].[2017].[Q1].[Feb].[17], then that Injuryis being included in the chart.
Is there a way I can restructure my MDX so that the bar for February does not show all data for February, but only the data for Fenruary that is >= ${mdxStartDateParam} and <= ${mdxEndDateParam}?

Answer 1

Since the Mondrian doesn't support sub-queries, you can't use your Calendar hierarchy for both where clause and axis. Also there is no way to filter days and show month only on axis. So, if you have two separate hierarchies for Days and Months, you may use the following:
WITH
SET [Date Range] AS [YourDateDim].[YourHierarchyNotInDateParam].[MonthLevel].Members
MEMBER [Measures].[Month Name] as [Incident Date.YQMD].currentmember.parent.parent.name || "-" || [Incident Date.YQMD].currentmember.name
SET [Classification Month Set] AS (
Hierarchize(
ORDER(
Hierarchize(FILTER([Classification].[Classification].members,[Classification].CURRENTMEMBER IN {Descendants([Classification].[${paramInjClass}])})),
[Measures].[Injury Count],
BDESC
)
) * [Date Range]
)
SELECT {[Measures].[Injury Count], [Measures].[Month Name]} ON COLUMNS,
NON EMPTY [Classification Month Set] ON ROWS
FROM [Injury Analysis]
WHERE {${mdxStartDateParam}:${mdxEndDateParam}})
Otherwise you have to deal with shown days and group them after.

Answer 2

Without knowing anything about the dialect of MDX you're using, or being able to see the dimension structure, my guess is that the problem is with the definition of [Date Range]:
SET [Date Range] AS {${mdxStartDateParam}.Parent : ${mdxEndDateParam}.Parent}
If the two parameters are at the Day level, does .Parent return their parent months?
The solution might be to make the date range be a set of days:
SET [Date Range] AS {${mdxStartDateParam} : ${mdxEndDateParam}}
and then aggregate by month somehow.