Thanks for asking :).
There is an implementation. Actually, Juraj ported it recently as part of the highly successful project of removing Mondrian. You can find it here:
HismoClassHistoryGroup>>viewEvolutionMatrix
An example, can be triggered via:
MooseSampleData current allClassHistories viewEvolutionMatrix
Typically, you should look for visualizations like this in methods called view*. The actual implementations are done in corresponding methods view*On: in the same class. In our case, we want to have the visualization available for a group of class histories, thus, we find it in the HismoClassHistoryGroup.
I presume that in your case, you need it for other types of entities. In this case, we should probably push the implementation in the superclass. Take a look and let us know if it works for you.
Cheers,
Doru