How to exclude duplicate values

Hi ALL,
Firstly, Ashish_Mathur Thank you for your solution!
And mclawler  ,you can use measure to write down the requirements you need to implement, and then aggregate them into a new table using summarize. 

CALCULATE(SUM(PCL_Data[Amount]),ALLEXCEPT(PCL_Data,'PCL_Data'[Customer Number])) 

We can use the rankx function to determine the first of the duplicate values as the return value,Fistly product As long as it is similar to Fistly pcl, you can change a few parameters.

FirstPCLMeasure = 
IF(
   CALCULATE(COUNTROWS('PCL_Data'), ALLEXCEPT('PCL_Data', 'PCL_Data'[Customer Number])) > 1,
   CALCULATE(
       MAX('PCL_Data'[PCL Increase/PCL New]),
       FILTER(
           'PCL_Data',
           'PCL_Data'[Customer Number] = MAX('PCL_Data'[Customer Number]) &&
           RANKX(
               FILTER('PCL_Data', 'PCL_Data'[Customer Number] = MAX('PCL_Data'[Customer Number])),
               'PCL_Data'[PCL Increase/PCL New],
               ,
               ASC
           ) = 1
       )
   ),
  MAX('PCL_Data'[PCL Increase/PCL New])
)

Finally in the aggregation by summarize to form a new table, the design of their own matrix

Table = 
SUMMARIZE('PCL_Data','PCL_Data'[Customer Number],"Amount",'PCL_Data'[measure],"A",'PCL_Data'[FirstPCLMeasure],"B",'PCL_Data'[FirstProductMeasure])

If you still have questions, check out my pbix file, I hope it helps!