Show in right bottom commodity cell corner:
Open site on commodity icon click:
Move the mouse over a commodity to highlight it's possible relation on the other ones.
Click on the planets buttons at the bottom of the frame to enable/disable their related resources and see what can and can't still be produced on different combinations.
Double click on planet button activates this planet, double click on single active planet activates all planets.
You can also individualy select the commodities when clicking on them to combinate them and highlight their possible output.
To help you with that, you can then press 'I' to select all the inputs of a commodity, 'O' for all it's outputs and 'P' for all it's pairable commodities.
Clicking on a commodity icon will open it's market details or bring other site if you are out of game.