Array sum measure based on values for other columns

Hi everyone,

I'm trying to create a measure for the sum of values (call this, 'Data'[V]) for each unique value in a column (call this 'Data'[C]. I thought it would be best to avoid creating a new table, though I am unsure In example, i would like a table like this:

to return:

However, there is currently also a single table used as a time horizon filter

and based on what the viewer chooses on the slicer with this data, performs a calculation based on the dates from the original table. 

I would like the grouped values from the top table to reflect the date filtering.

Is this possible?

Thanks