"Other" category for small values in Donut/Pie chart

[BITomS]

I have a scenario where I have a lot of categories for a particular dimension in my model and the breakdown of all of these need to go in a donut/pie chart. I can't find a simple way of setting a threshold (say 3%), so if anything makes up a proportion less than this, it gets grouped into a single category of 'Other'. This would improve end user visibility as we still want to include what this other % is, but don't want all the segments as it gets very busy!