How to add an aditional top x-axis description in a Heatmap figure and repeat xlabel values?

Dear all, I am trying to plot to following heatmap (Image changed to comply to the desired output):

the problems that I am facing are:

1) I cannot repeat xlabes values (have duplicate values in the xlabel)... I get the error:

Error using heatmap (line 53) Vector of x values contains duplicate values.

bat_simp = heatmap(xval,yval,B);

2) I cannot manage to find a way to add another top x-values label ('Present', 'Future A', and 'Future B')

Any Ideas on how to get around these problems?

Best wishes,

Luan