Field Parameters, NOT Calculation Groups. SELECTEDMEASURE() functionality without Tabular Editor

FIELD PARAMETERS or CALCULATION GROUPS?
Both are used to dynamicaly change fields/measures in your report/visual.
I would recommend to start with Field Parameters, as far as:

1. It's more modern feature.
2. Covers Calculation Groups functionality.
3. Don't need external tools (like Tabular Editor).
4. You could use it together with over fields/measures.
5. Supports  individual values columns sort in matrix (How to sort values in pivoted columns) 

My favourite tutorial video for this topic by AlbertoFerrari : Fields parameters in Power BI

Just one problem: how to pass selected measure as variable for another measure?
Example:
I have two almost identical measures: 

YTD Sales = CALCULATE([Sales], DATESYTD('Calendar'[DateKey]))

and

YTD Quantity = CALCULATE([Quantity], DATESYTD('Calendar'[DateKey]))

But I want to reduce amount of measures and use something like

YTD = CALCULATE([Melected], DATESYTD('Calendar'[DateKey]))
//[Melected] - Measure sELECTED 
//           - measure that could be equal [Sales] or [Quantity] depending on our slicer single choice/election

Here is amazing video by pleblanc  dedicated to this topic:
REDUCE the # of measures with Calculation Groups In Power BI

Question: is it possible to get SELECTEDMEASURE() functionality without Tabular Editor?
Answer: Yes
Details: Desired functionality:

How To, a 5-step guide (the initial two steps being the focus of this article)

1) Let's create _MeasureSelected table and use it's [Melected Name] column as single choice slicer in our report:

2) Create [Melected] measure, that will be equal [Sales] or [Quantity] based on [Melected Name] slicer single choice:

3) Create [Melected] dependent measures like:

4) Create Field Parameter with list of measures:

5) Create matrix and Enjoy result

P.S. Source file (Download)