how bypass different subnet on HotSpot without traffic sign

Hello Friends

my network is this :

3 department
1 root department
and 1 server has a root department
servers (esxi) ip : 10.10.10.0/24
department 1 ip : 192.168.70.0/24 and run Hotspot
department 2 ip : 192.168.80.0/24 and run Hotspot
department 3 ip : 192.168.60.0/24 and run Hotspot
all department need to be connected to the server with or without login to the Hotspot
Is there a way to send and receive traffic to the server in the user account Not recorded Because all users Traffic account very soon to expire.

Is ip>firewall>Mangle settings should be done?
please help me !

anybody no idea?