DAX SUMX Multiple Hierarchy Level Query

[Badger43]

Hi I am trying to return values from a 'Rates' table linked to the below 'MU' table on the Parent dimension (one MU to Many Rates)

I am using the formula SUMX( VALUES ( MU[Parent] ) ,[Allocation %]) where Allocation% is a sum of the 'Rates' table values.

This works fine, however, in some instances there will not be a value for MU([Parent]) in the 'Rates' table.  In this instance I would like to return the values linked to the 'Dept' column instead (which will neccessitate a many to many inactive relationship).

I am unable to successfully write a measure which substitues this 'Dept' link and then still consolidates the values correctly at total level.

I have tried something such as the below where I try and check whether the value exists and then substitute if not, and this works for individual rows but the totals are incorrect.

Have been stuck almost a full day on this, any help you can offer would be greatly appreciated.  Thanks in advance.

VAR hasvalue=CALCULATE([Allocation %],ALL(Rates[Stage],Rates[TA],Rates[Project Code]))

VAR dcode=

        CALCULATE([Allocation %],USERELATIONSHIP(MU[Dept],Rates[MU Code]),CROSSFILTER(MU[Parent],Rates[MU Code],None))

VAR pcode=

        [Allocation %]

RETURN

    SUMX(VALUES(MU[Parent]),if(hasvalue=0,dcode,pcode))

Link to demo file....https://drive.google.com/file/d/18PllpMYNDgzm3ck9pThhFGrCkZu78bmi/view?usp=sharing 

[Badger43]

@lbendlin thanks very much for your reply and sorry I wasn't clearer.  I was anonymising and simplifying the full model and only got so far in the time I had.  I have reloaded the file with full renaming, and also update the formulas in my original post to take account of this.

In the MU 'Parent' column there are no gaps, but in some instances (for the RBU2 Series of the rates table) there is no corresponding value in the rates table.  At this point I would like it to use the values which would be linked on the MU'Dept' column instead.

Hope this makes things clearer and again a solution for this would be much appreciated.

Thanks again

Mark

[lbendlin]

In the MU 'Parent' column there are no gaps, but in some instances (for the RBU2 Series of the rates table) there is no corresponding value in the rates table. 

You lost me. I cannot see where the gaps are.

[lbendlin]

There is no Rates table in your sample data, and I don't see any gaps in the Parent column.  Please clarify.