Single target, Small target, Target group – OM SYSTEM OM-5 Mirrorless Camera with 12-45mm f/4 PRO Lens (Silver) User Manual
Page 92: Target group (3 × 3)

Select a single focus target.
M
Further reduce the target size for single-target AF-target selection.
Use for pinpoint focus on small subjects.
o
Select a group of 5 targets, arranged in a cross. The camera chooses
the target used for focus from within the selected group.
n
Select a group of 9 targets, arranged in a square. The camera
chooses the target used for focus from within the selected group.
r
X
Single Target
Z
Small Target
Y
5-Target Group
r
9-Target Group (3 × 3)
92
Choosing an AF Target Mode (AF Target Mode)