Variable sized array of bus signals?

Hi everyone,

I defined a bus object in Matlab (Bus1), and a For Each block in simulink which outputs a fixed sized array of bus signals (20*Bus1), then I want to take them through a block where I could select certain buses and outputs them(in variable size), but in the Model explorer I can't set the output of a block to variable-size if it's a Bus. Anyone had the same problem before? Is there any way to work around it? Thanks a lot for any help.