Creating a Flag from 2 Value-Columns

Hello,

I currently have a stacked bar chart with the following data. The chart currently sums the ED and MIU Attendances together and then stacks by Provider.

I have now been asked if we can filter by ED and MIU Attendances.

This is a snapshot of my data table (please note that I have about 10 other columns of data to contend with):

Provider         Date                    ED Attendances        MIU Attendances

ABC                17/07/2016          10                              5

DEF                17/07/2016           12                              9

GHI                17/07/2016           15                              5

ABC               24/07/2016           12                              4

DEF               24/07/2016            11                              6

GHI               24/07/2016            18                              5

I am looking to add a column that will flag ED and MIU so that I can then use a filter.

Any help is much appreciated. Thanks in advance