2 tables on Bar of Pie, Is it possible?

Hi All…
Say, we got a table ‘A’ and Category 4 is one of the categories in table A. We want to emphasise on the chart, Table B, which is items of Category 4, where as we don’t care as much to the items of category 1-3.
Table A
Category 1
Category 2
Category 3
Category 4 -> Table B
Item1
Item2
Item3

Is it possible to do it from 2 Data series?… My current solution right now is like this, put it one table with category 4 straight away broken down to item 1 to 3

Table A
Category 1
Category 2
Category 3
Item1
Item2
Item3