I recently got asked to make a 3 tiered cake with buttercream including the filling. I thought this might be a little too much buttercream. Do folks use the same buttercream for the filling as they do icing the cake? Or is there a suggestion for making the filling slightly different??? Help!

Yes you use the same b'crfeam for fill as you use for the icing.
If the customer has requested b'cream fill then you don't make it different - you give them what they asked for About the only thing one could do is add more or different extract to the b'cream.
For future orders you can suggest different fillings. YOu can alwasy add fruit jams to b'cream to change them some.

I used regular BC icing as filling for 25 years. Never even thought about using anything else ... that's just how it was done way back then and that's what I kept doing. I still get brides who want it that way.

Buttercream is actually the default filling used when "no filling" is requested.

Using a different flavored b/c for the filling than that used for frosting/decorating the cake would be slightly different without being too difficult.

Icing fruit is good for fruit flavered b/c fillings:

http://www.cakecentral.com/cake-decorating-ftopict-591057-.html

HTH

Thanks for all your responses. I will go with what the customre requested (even though I tried to suggest other fillings)