How can I assign participants to 4 conditions which should be grouped as 2 in a longitudinal study?

Hi there, I am currenty preparing survey for my thesis.I have 4 groups; visual-immersed, visual-distanced, linguistic-immersed and linguistic-distanced as experimental conditions.I want to randomly assign participants to one of these four conditions.I used randomizer with blocks to do this.Here is my problem, there are two sessions in the study. I want participants who were in visual immersed condition in time 1 to assign to visual distanced condition in time 2; and visual distanced to assign to visual immersed.It is the same logic with linguistic conditions. So, visual and linguistic conditions should not be mixed. How can I do this?