Use
[CTRL] + [SHIFT] + [G]
to group 2D masks together. Go check out
2D Group mask
Blend multiple 2D masks together
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documentation for more details
This type of grouping allows you to group 2D masks to organize your compositions.
This is a 2D equivalent of the
3D masks Group
A Group of 3D Mask
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.
2D Modifiers Group