Do you need to foil wrap all of the cake circles used in a 3 tier stacked cake or is just the cake circle enough?

Not quite sure this is what you mean, but if you are talking about the cake boards that are supporting the tiers, I do cover them completely with foil and I also put a circle of parchment over the crusted over icing on the lower supporting cake, insert dowels, sprinkle some icing sugar and then place the next tier. The reason it is a good idea to seal the support boards is that the moisture from the cake and icing can get into the cardboard and cause it to warp which could cause some issues with the cakes.
Hugs Squirrelly

Thats what I thought. Thanks for the help. I havent done a stacked cake in a while and I just wanted to make sure. Thank you for your help.

I think a lot depends on how long the cake sits too. I had a pal that did a stacked wedding cake and covered the bottom and top of the boards, but not the side. It sat for 48 hours before the wedding and in that time, the boards absorbed the moisture into the sides where she had the borders and the cake went a little lopsided looking from the boards swelling unevenly. That is why I am extra cautious.
Good luck with your stacked cake, I am sure it will be lovely!
Hugs Squirrelly

I decided to take your advise. Thank you for your help.