border format in custom cells

[shin_oomura]

I want to erace border lines or make the color white among the same group in Straight Table (not Pivot Table), like below chart,

grp1 grp2 ID var
----------------
A    A    1  100
---------------- <- erace or white color
A    A    2  200
---------------- <- erace or white color
A    A    3  100
---------------- <- default color
A    B    4  200
---------------- <- default color
B    B    5  300
----------------

I tried "custom cells" or "above" function, but it didn't work.

Please give me some advice.
Regards.

shin

[shin_oomura]

Isn't it the right category to post this question ?

I would like to let me know the right category.

regards.