Hi @poperator
Yes, the backward static route is required on the vpn-instance vpn2, and the destination address should be the source IPs those need to access the vpn2.
please refer the example below:
R1---------(vpn-instance vpn1 G0/0/0) R2 (G0/0/1 vpn-instance vpn2)----------R3
R2:
#
ip route-static vpn-instance vpn1 0.0.0.0 0.0.0.0 vpn-instance vpn2 10.2.2.2
ip route-static vpn-instance vpn2 0.0.0.0 0.0.0.0 vpn-instance vpn1 10.1.1.2
#