Overlapping subnets. NAT

Question

Cisco

There are two intersecting 9.0/24 subnets. It is necessary that users from the 75th subnet can get into the upper 9th subnet, how can this be done?
clip2net.com/s/ibkQzi

Answer 1

Look towards Policy Routing (on the lower router)

Answer 2

If it is not necessary from the 75th network to the lower one, then you can try to drag it simply as a vlan to the upper router.

Answer 3

Judging by the mask, the connection between R1 and R2 is L2.
If you make a single L2 domain between all three routers and give R3 the address 192.168.90.3, then you can do without PBR. Only in order for hosts with the same address from both networks (9.0) to have access to 75.0, you will have to fence oncoming NATs.