Canon EOS 7D Mark II Basic Instruction Manual page 86

Lenses and Usable AF Points
Group G
AF is possible with the center AF point and the adjacent AF points
above, below, on the left, and on the right. Only the following AF area
selection modes are selectable: Single-point AF (manual selection),
Single-point Spot AF (manual selection), and AF point expansion
(manual selection
If an Extender is attached to the lens and the maximum aperture is f/8
(between f/5.6 and f/8), AF will be possible.
86
).
: Cross-type AF point. Subject
tracking is superior and high-
precision focusing is achieved.
: AF point sensitive to vertical lines
(top and bottom AF points adjacent
to the center AF point) or horizontal
lines (left and right AF points
adjacent to the center AF point).
Not manually selectable. It works
only when "AF point expansion
(manual selection
: Disabled AF points (not displayed).
)" is selected.