I have a question about Numbers.

I want to make a bar chart that shows the membership of my organisation.

I want to divide between unitary organisations and membership organisations, so i want there to be 2 bars.

But on the bar for membership organisations, I want it to be divided by a categorisation of "how many members". The 4 categories would be <30, 30-100, 100-500 and 500+.

so for example the numbers would be

- Unitary organisations 3
- Membership organisations 11 (<30=2, 30-100=4, 100-500=3, 500+=2)