Measure to include current selection and rows above and below dynamically

Hey, 

maybe the attached pbix file provides what you are looking for.

Please be aware that I unpivoted your sample data, this means I transformed from wide (many columns) to long (many rows)

As Greg_Deckler already mentioned an unrelated table is necessary to select the country.

Then then there are some measures

• SELECTED Country (can be hidden)
  this measure returns the selected country from the unrelated table
• SUM Amount across ALL Years (can be hidden)
  this measure sums the value across all the years, this measure is the basis for the ranking
• rank Countries (can be hidden)
  this measure ranks the measure [SUM Amount across ALL Years] for all the countries
• RANK of selected Country (can be hidden)
  this measure returns the RANK for the selected country and is used in the final measure to filter the counries (below and above accordingly)
• map Amount
  this is the final Measure, basicall this measure works like this
  
  • create a table that contains the selected country from the unrelated table / slicer,  the three countries that are above (a greater rank), and the three countries that are below (a smaller rank), 
  • use this table to filter the countries

This measure looks looks like this

map Amount = 
var countriesAboveAndBelow =     
UNION(
FILTER(
	FIRSTNONBLANK('Table1'[Country],1)
	,'Table1'[Country] = [Selected Country]
	)
,
UNION(
SUMMARIZE(
        FILTER(            
            ADDCOLUMNS(
                GROUPBY(
                    'Table1'
                    ,'Table1'[Country]
                )
                ,"theRank", [rank Countries]
            )
            ,[theRank] > [RANK of selected Country] && [theRank] <= [RANK of selected Country] + 3
        )
,Table1[Country]
)
,SUMMARIZE(
        FILTER(            
            ADDCOLUMNS(
                GROUPBY(
                    'Table1'
                    ,'Table1'[Country]
                )
                ,"theRank", [rank Countries]
            )
            ,[theRank] < [RANK of selected Country] && [theRank] >= [RANK of selected Country] - 3
        )
,Table1[Country]
)
)
)
return

CALCULATE(
    SUM(Table1[Amount])
    ,countriesAboveAndBelow
)

Hopefully this is what you are looking for

Regards

Tom