Sales from last year according to mapping table

[macarenamadrid]

In Power BI I have several tables: one fact table with all the data (fctOrders), one dimensional table for the dates (dimDate) and one auxiliary table for the dates (dimEquivalente).

This last table dimEquivalente has only two dates column: first column has all the dates from this year, and second column has one date from last year. For example, the date third of March of this year is mapped with fifth of March from last year. Or 10th of July from this year is mapped with 15th of July.

I have made the relationship in the model tab between dimDate[Date] and dimEquivalente[Fecha], so that when a date for this year appears, it also shows the related date of last year according to dimEquivalente mapping.

Now the goal is to make a measure that shows all the sales from last year, according to the dimEquivalente table mapping (row 10th of July this year should show sales from 15th of July of last year). I used the formula "CALCULATE([Total Ventas], dimEquivalente[Día Equivalente])" but it doesn't provide what I need. It shows the sales from this year, not from the appropriate mapping from last year. How can I create that DAX measure?

[Greg_Deckler]

@macarenamadrid Sorry, having trouble following, can you post sample data as text and expected output?
Not really enough information to go on, please first check if your issue is a common issue listed here: https://community.powerbi.com/t5/Community-Blog/Before-You-Post-Read-This/ba-p/1116882

Also, please see this post regarding How to Get Your Question Answered Quickly: https://community.powerbi.com/t5/Community-Blog/How-to-Get-Your-Question-Answered-Quickly/ba-p/38490

The most important parts are:
1. Sample data as text, use the table tool in the editing bar
2. Expected output from sample data
3. Explanation in words of how to get from 1. to 2.