Breakback on List items

Hi All,

I have a list product list P4 and a filter is applied on it i.e at P4 level only few items should be shown based on selection.

Break back is enabled on all levels.

In P4 5 items are there only 2 items  belongs to category 1 and 3 items to category 2. Our requirement is that If user select Category 1 and enter data at P3 data should split only for 2 items  & if Category 2 is selected data at P3 data should split only for 3 items.

P3 Data entered -10000               P3 Data entered -10000 

category 1 - selected                    category 2 - selected 

ITEM 1- 3333.33                            ITEM 2- 5000

ITEM 3- 3333.33                            ITEM 5- 5000

ITEM 4- 3333.33

Need a workaround on this when break back is applied.

Thnaks

Sri Nitya