I solved the problem using 2 new formula columns
The Group column formula just creates a grouping number when :Big Value is detected
If( Row() == 1, theGroup = 0 );
If( Is Missing( :Big Value ) == 0,
theGroup
++);
theGroup;
The Sum column formula just looks one row ahead, and if it detects a non missing value for :Big Value, it adds up the sums for both :Value and :Big Value for the current Group and then adds them together
If( Is Missing( :Big Value[Row() + 1] ) == 0,
Sum( Col Sum( :Value, :Group ), Col Sum( :Big Value, :Group ) ),
If( Row() == N Rows( Current Data Table() ) & Is Missing( :Big Value ) == 0,
Sum( :Value, :Big Value )
)
)
Attached is the data table I used
Jim