Hi Jim,
Not possible this way: %SELECTION% and %SELECTION2% resulted from PROMPT(SELECT... has prefix that can't be combined like:
TASK(/CPMB/CLEAR_CUBE,SELECTION,%SELECTION%%SELECTION2%)
You can use PROMPT(COMBOBOX, %VER%,...) with the fixed list of members, then you can append %VER% to %SELECTION% like:
TASK(/CPMB/CLEAR_CUBE,SELECTION,%SELECTION%DIMENSION:VERSION|%VER%|)
where %SELECTION% is your %SELECTION2%
Vadim