Communication between multiple subnets

Good day.

Need help with establishing communication between multiple subnets under different interfaces.
My configurations are below.

L2TP VPN - 192.168.90.0/24
Ether1 - WAN1 << PPoE based from ISP
Ether2 - 192.168.70.0/24
Ether3 - 192.168.65.0/24

When I am connected to the L2TP VPN from external network, I want to access a device which is connected to Ether2.

or a device which is connected to Ether3, can be accessed by a client on Ether2.

Please help.

I think that the L2TP should in theory be able to access all subnets if there aren’t any drop firewall rules. For the connection between ether3 and ether2:

/ip firewall filter add action=accept chain=forward src-address=192.168.65.0/24 dst-address=192.168.70.0/24

Thanks mate.

The below subnets are part of different hotspot network which require authentication.
Ether2 - 192.168.70.0/24
Ether3 - 192.168.65.0/24

Shall the above filter rule still work?

Most probably yes. If not, an IP binding on the ether3 server should do the trick

IP binding or rules nothing works bro.

How about adding a walled garden rule:

/ip hotspot walled-garden ip add action=accept server="ether3_server" src-address=192.168.65.0/24