3D L-system

I have a question for a project that I am working on. I set up a rule system for attaching geometry to one another,(A>B & C, B>A & B, C>C & D, D dies). The letters correspond to different geometry, varying in size and I wanted to know if there was a way to use grasshopper to set any geometry that I create and attach them to one another according to this code. It is like a 3 dimensional L-system and I wanted to know if there was a way of creating it in grasshopper with my own geometry so that I can control some of the parameters but still allow it to generate and grow a specific amount on a surface or solid in rhino. Thank you.
I am attaching a rhino file which shows the idea of what I am trying to acheive. It has two different sets of geometry with two different variations of growth. If there is a way of setting up a grasshopper definition for this, would it also be possible to change the code(for example, A>B,C,&D, B>A, C>B, D>C...) within grasshopper so I can use the same base geometries(A,B,C,D) to genrate different forms according to the code? Thanks once again.