Get individual values from table1 where table1 column = table 2 column then sum

I have fixed my own issue. 

The problem was for some reason the query is using Max / Min from the string comparison cells and using that to calculate total value . Not sure why it does that because I used SUM (value) and my filter used MAX(group type) comparison.

I changed the first measure to this:

Overhead Budget Calc = 
CALCULATE(
    SUM('BudgetData21-22'[Value]), 
    FILTER('BudgetData21-22', 'BudgetData21-22'[GroupType] = SELECTEDVALUE('cwDashOverHeads-KPI10'[OverheadType]))
    )

This made the total blank which I then used an if else statement to do a conditional calculation.

total sum OH = 
IF(ISBLANK(CALCULATE('cwDashOverHeads-KPI10'[Overhead Budget Calc])), CALCULATE(SUM('BudgetData21-22'[Value])), [Overhead Budget Calc])

Works perfectly. 

Thanks to those who tried to help.