If you want to connect one LEVEL switch to each display, that will work fine assuming that the display that the switch is connected to is online to recognize the button push.
If you want to connect both LEVEL switches to one display, just split the single connection to Pin 28 to each switch.
If you want to be fully redundant -
both LEVEL switches connected to
both displays, a bit of work (adding diodes) is required - see Installation Options For External LEVEL Button on Multiple SkyView Displays, pages 10-14 and 10-15 in
SkyView System Installation Guide, Rev U.
I have a D1000 & a D700. Both have level switch inputs. Do I separate them (I.e. One on each stick) or gang them together?