Filter expression (dependency between slicers)

I have 3 slicers.
First is 'Month before' where I can choose count of months before current month
Second is 'Month after' where I can choose count  of months after current month
Third slicer shows month's names which depedented of choosen result in first two slicers.

I tried to create table with filtered results, but this results are not working dynamicaly. When I picking diferent results in first 2 slicers, there is no change in third one. How I can fix it? 

Example of created table:

MonthsTable = 
var MonthBefore = COUNT('Before'[Months])
var MonthAfter = COUNT('After'[Months])
RETURN 
FILTER('MonthName'; 'MonthName'[FilterNumber] >= MonthBefore * -1 && 'MonthName'[FilterNumber] <= MonthAfter)