creating mask with a group of objects

[WOIEJO]

Hello! I would like to know how I can make a mask of multiple objects, in this case, four squares (selected above). I grouped the squares and tried to make a clipping mask, but that did not work out. Do I have to send to back an image for every square mask I want to create? Thank you for your time!

[Ton Frederiks · Accepted solution]

You can try to first make them into a Compound Path and then use that as Clipping Mask.

[WOIEJO]

I tried making a compound path, but one of the squares went transparent.. did I do something wrong?

[WOIEJO]

I think it had something to do with the fact that I used the transform effect under "Distort & Transform" to create the spaced out copies. I remade the grid just using shapes and smart guides and did not see any issues with making a mask. Thank you for your time, I really appreciate it!