Hi,
Try this,Select Group 2 then right click select format field then select the font Tab .Then Click the X+2 button against the Style and enter the formula below
IF DRILLDOWNGROUPLEVEL = 0 then
crRegular
else
crBold
Do the same for Group 3 and enter the formula below
IF DRILLDOWNGROUPLEVEL = 2 then
crRegular
else
crBold
what you need to do is check the DRILLDOWNGROUPLEVEL of each group and adjust the bold unbold accordingly,which can be done creating a separate formula ......
cheers
Rahul