Have a look at these menu settings:
d16 - Virtual horizon type. A is like a plane’s VH, B is two lines at the bottom and right of the display.
d17 - Custom monitor shooting display - For the LCD - 5 options, first 4 programmable if you highlight an option and press the right side of the ring surrounding the OK button. You can enable the VH here amongst other things.
d18 Custom viewfinder shooting display - same as d17 but for the viewfinder. There are only 4 options, all programmable.
The Circle shows the centre weighting area for centre weighted metering - it only appears when that metering pattern is selected.
Use DISP to cycle through displays.
g16 and g17 set the display options for video shooting - similar process but the VH is the one selected in d16.
It might be worth you investing in
@Steve Z8 & Z9 setup for wildlife e-book?