I used this to access devices in 192.168.1.0/24 subnet:
add action=src-nat chain=srcnat src-address=192.168.2.0/24 to-addresses=192.168.1.240

Basically pretending to be 192.168.1.240 to access 192.168.1.xxx from 192.168.2.0 subnet devices.

I just tried to set this up in new router OS 7, and it doesn't seem to work.

Should it work, and if not, is there another way?