Column changing based on filter

Hi,

I have two groups that contain differently grouped names for accesories: Group1 and Group2. I also have a Matrix were this group is used as rows. What I want to have is when the filter for month is < August 2021, I want to use Group1 as  rows, and when the month filter is >= August 2021, I want to use Group2 as rows. Below simple visual presentation.

When it is filtered on < August 2021

When it's filtered > August 2021 

Basically what happend in August is that the components of the groups changed and I still need to keep the visual representation for before August and after.

I tried doing SELECTEDVALUE and SWITCH, however I couldn't create a measure that allow for it.

Thank you