How to create "multi-stacked" 100% height charts?

I have a list of 2 variables. For each variables, I have 3 possible choices. When a user makes a “request”, he has to choose a value for the 2 variables.

I want to make a graph that represents, for each months, the statistics of those variables: the percentage of each choices for each variables.

The only solution I’ve found so far is to create a 100% height “stacked” charts. For one variable, it looks like this:

100% height "stacked" chart for one variable

With 2 variables, I need to have 2 columns for each months.
Is it possible to do this with Chart.js, and if so, how?

Source: stackoverflow-javascript