You should be able to accomplish this by adding two linear constraints to the design. From the picture, it appears that Component A ranges from 0.2 to 0.3. Component B from 0.45 to 0.8. And Component C ranges from 0 to 0.25. Based on that information, if you can provide the coordinates for the points highlighted in red (a zoomed in version of your picture) the linear constraints can be defined. Note that I am assuming that the start of the one constraint is for A at 0.25 and B at 0.75.
Dan Obermiller